Elements of morphology: Standard terminology for the hands and feet

Article (PDF Available)inAmerican Journal of Medical Genetics Part A 149A(1):93-127 · January 2009with113 Reads
DOI: 10.1002/ajmg.a.32596 · Source: PubMed
Abstract
An international group of clinicians working in the field of dysmorphology has initiated the standardization of terms used to describe human morphology. The goals are to standardize these terms and reach consensus regarding their definitions. In this way, we will increase the utility of descriptions of the human phenotype and facilitate reliable comparisons of findings among patients. Discussions with other workers in dysmorphology and related fields, such as developmental biology and molecular genetics, will become more precise. Here we introduce the anatomy of the hands and feet and define and illustrate the terms that describe the major characteristics of the hands and feet.
RESEARCH ARTICLE
Elements of Morphology: Standard Terminology for the
Hands and Feet
Leslie G. Biesecker,
1
* Jon M. Aase,
2
Carol Clericuzio,
3
Fiorella Gurrieri,
4
I. Karen Temple,
5
and Helga Toriello
6
1
National Human Genome Research Institute, NIH, Bethesda, Maryland
2
University of New Mexico School of Medicine, Albuquerque, New Mexico
3
University of New Mexico School of Medicine, Albuquerque, New Mexico
4
Institute of Medical Genetics, Catholic University of Rome, Rome, Italy
5
Wessex Clinical Genetics Academic Group, University of Southampton, Southampton, United Kingdom
6
Spectrum Health, Grand Rapids, Michigan
Received 25 September 2008; Accepted 15 October 2008
An international group of clinicians working in the field of
dysmorphology has initiated the standardization of terms used
to describe human morphology. The goals are to standardize
these terms and reach consensus regarding their definitions. In
this way, we will increase the utility of descriptions of the human
phenotype and facilitate reliable comparisons of findings among
patients. Discussions with other workers in dysmorphology and
related fields, such as developmental biology and molecular
genetics, will become more precise. Here we introduce the
anatomy of the hands and feet and define and illustrate the
terms that describe the major characteristics of the hands and
feet. Published 2009 Wiley-Liss, Inc.
{
Key words: congenital abnormalities; terminology; anatomy;
anthropometry; hands; feet; congenital limb deformities; nails;
malformed nails; dermatoglyphics
INTRODUCTION
This paper is part of a series of six papers defining the morphology
of regions of the human body [Carey et al., 2009; Hall et al.,
2009; Hennekam et al., 2009; Hunter et al., 2009; Allanson et al.,
2009b]. The series is accompanied by an introductory article
describing general aspects of this study [Allanson et al., 2009a].
The reader is encouraged to consult the introduction when using
the definitions.
An early classification of limb anomalies is that of Isidore
Geoffrey Saint-Hilaire (secondary citation, not reviewed).
This classification divided anomalies into three categories
(phocom
ele, hemim
ele, and ectrom
ele). A more recent classifica-
tion is that by Frantz and O’Rahilly [1961]. Modifications of this
scheme were implemented by others [Swanson et al., 1968; Swan-
son, 1976]. These schemes are hierarchical classifications and most
do not include definitions of the terms.
The similar, but distinct, system of Temtamy and McKusick
[1969] was developed. Most of the seven categories that
they defined were subdivided into syndromic and non-
syndromic forms. While this approach is clearly useful when the
goal is to define distinct diagnostic entities, it is not appropriate
for a purely descriptive endeavor. The Temtamy and McKusick
system focuses on terms for commonly observed patterns of
anomalies, not individual structures. Findings that do not conform
to commonly recognized patterns cannot be described by their
system.
Poznanski [1984] lists a glossary of terms used to describe
abnormalities and variants of the hands (his text does not address
the foot). These definitions are insufficient for a terminological
effort such as is undertaken here. However, some are a starting point
and others are listed below as being replaced by a more precise term.
Finally, the textbook by Aase [1990] includes a number of defi-
nitions that were also useful.
*Correspondence to:
Leslie G. Biesecker, National Human Genome Research Institute, National
Institutes of Health, 49 Convent Drive 4A80, Bethesda, MD 20892-4472.
E-mail: leslieb@helix.nih.gov
Published online 5 January 2009 in Wiley InterScience
(www.interscience.wiley.com)
DOI 10.1002/ajmg.a.32596
How to Cite this Article:
Biesecker LG, Aase JM, Clericuzio C, Gurrieri
F, Temple IK, Toriello H. 2009. Elements of
morphology: Standard terminology for the
hands and feet.
Am J Med Genet Part A 149A:93127.
Published 2009 Wiley-Liss, Inc.
{
This article is a US Government work and, as such, is in the public domain in the United States of America. 93
General Descriptors and Background
for the Terms
1. The use of the word ‘‘digit’’ versus ‘‘finger’’ and ‘‘toe’’ is
problematic. ‘‘Finger’’ is usually specic to digits 25 of the
hand and ‘‘toe’’ to digits 25 of the foot whereas ‘‘digit’’ is a
more general term that can be used to describe any nger or toe.
We generally use the word ‘‘finger’’ to be distinct from
‘‘thumb’’ (pollex, although this latter term is used rarely in
English) and ‘‘toe’’ is distinct from ‘‘hallux’’ (which, oddly
enough, is more commonly used in English than is ‘‘great toe’’).
It is important for the user to read the denition to understand
the context in which the term ‘‘finger’’ or ‘‘toe’’ is used. We
recognize that some languages do not use a term equivalent to
‘‘finger’’ and ‘‘toe’’ and instead use a modier of digit (e.g., dita
della mano). The term ‘‘ray’’ is a yet more general term that can
refer to a nger, toe, thumb, or hallux, but it also includes
metacarpals/tarsals, whereas ‘‘digit,’’ ‘‘thumb,’’ ‘‘hallux,’’
‘‘finger,’’ and ‘‘toe’’ only refers to the phalangeal segments of
the ray. The term ‘‘ray’’ is little used in this terminology.
2. The proximo-distal axis of the digits is specied according to
the name of the underlying bones, for examples, the portion of
the nger overlying the distal phalangeal bone is the distal
phalanx of the nger.
3. The digits are numbered 15 (or 6 or more in patients with
polydactyly) from the radial/tibial side of the limb, starting
with thumb/pollex (great toe/hallux) to little nger/toe; ‘‘F’’
denotes that they are ngers, ‘‘T’’ denotes toes. It is acknowl-
edged that identifying the thumb as ‘‘F1’’ contradicts the
notion that this digit is designated as ‘‘thumb’’ instead of
‘‘first nger’’, but for simplicity this has been used. In the case
of polydactyly, if one can determine the origin of the duplicated
digit (e.g., for a partially duplicated thumb where a relatively
small digit emanates from the distal rst metacarpal, and it is
clearly a partially duplicated thumb and not an index nger, the
duplicated digit is sub-labeled A and B, with A used for the
more anterior (radial/tibial) sub-digit. In this case, the six digits
are numbered F1A, F1B, F2, F3, F4, and F5. If the origin of the
supernumerary hand digit cannot be clearly ascertained, the
digits are labeled F1, F2, ..., F6. We recognize that the latter
scheme leads to issues comparing pre- and postoperative digit
identiers.
4. Joint specication: interphalangeal joints ¼ IPJ (which is a
general term for ngers and toes but is a specic term for the
normal thumb and hallux, as they have only a single IPJ) with
use of the more specic terms distal IPJ (DIPJ) for the joint
between the middle and distal phalanges and proximal IPJ
(PIPJ) for the joint between the middle and proximal phalanges
of any triphalangeal digit. The metacarpal-phalangeal joint is
abbreviated as the MCPJ and MTPJ is used for the metatarsal-
phalangeal joint.
5. Fingertip. The distal segment of the digit overlying the distal
phalanx of the nger and including the nail, and dorsal and
ventral surfaces.
6. Descriptions should specify bilateral vs. right or left for laterally
paired structures. We do not specify terms for ndings of
asymmetry. Instead, we endorse the approach of dening a
body part as small or large, which is less ambiguous and reduces
the number of terms that must be dened.
7. The axes of the limb are specied as per embryological termi-
nology. AnteriorPosterior (A/P) (from the thumb/great toe to
the little nger/small toe), DorsalVentral (D/V) (from the
back of the hand/top of the foot to the palm/sole), and
Proximo-Distal (P/D) (from the shoulder/hip to the ngers/
toes). Note that common medical usage often substitutes the
terms ‘‘preaxial’’ for anterior and ‘‘postaxial’’ for posterior.
8. There are some denitions where one term applies only to the
feet and a similar second term applies to the hands. For others, a
single term for all limbs may be used with a modier for ‘‘feet’’
or ‘‘hands,’’ as appropriate. The terms were set out this way
primarily for convenience, as some of the terms, denitions,
and comments are cumbersome or awkward if one tries to
dene them in terms of both hand and foot features. In some
cases, the denitions were substantially different owing to
distinct anatomic features of the hand or foot.
9. For a few of the features, the position of the patient is important
(e.g., pes planus). In those cases, the positioning of the patient is
discussed in the comments for the term.
10. Note that radiographs are not used in this terminology. See
Allanson et al. [2009b] for a discussion of this issue.
11. The terms are organized alphabetically in three sections
(‘‘Hands and Feet’’, ‘‘Creases’’, and ‘‘Nails’’). We use the
singular form as the default for all terms. For some terms, the
singular form cannot exist (e.g., Cutaneous syndactyly of
the toes). In such cases, the singular and plural forms of a
word are mixed (e.g., ‘‘Toe’’ and ‘‘Toes’’), alphabetized by the
next word of the term. No attempt was made to hierarchically
organize the terms. The primary or preferred form of each term
appears in the paper in bold and italic font, except within the
comments section for that term.
DEFINITIONS
Hands and Feet
Acheiria: See Hand, absent
Acromicria: See Hand, small
Adactyly
Denition: The absence of all phalanges of all digits of a limb and
the associated soft tissues (Fig. 1). objective
Comment: This descriptor does not require absence of the
metacarpal or metatarsal bones. A qualifying phrase is added to
specify which limb has the attribute of adactyly.
Replaces: Aphalangy
Amniotic band: See Digital constriction ring
Aphalangy: See Adactyly
Apodia: See Foot, absent
Arachnodactyly: See Finger, long; Toe, long; Finger, slender; Toe,
slender
94 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Arch, dropped or fallen: See Pes planus
Arch, high: See Pes cavus
Brachytelephalangy: See Finger, short distal phalanx of; Toe, short
distal phalanx of
Camptodactyly
Denition: The DIPJ and/or PIPJ of the ngers cannot be extended
to 180
by either active or passive extension (Fig. 2). subjective
Comment: Note that some restrict the use of the term to inability
to extend the PIP joint of the fth nger. We do not restrict the term
in this way. This term should not be used if the patient has Clenched
hand. A similar effect can be created by radial angulation within the
distal phalanx with thickening of the epiphysis, which is called
Kirner deformity or dystelephalangy [Ozonoff, 1992]. The affected
digits should be specied.
Replaces: Streblodactyly
Clinodactyly
Denition: A digit that is laterally curved in the plane of the palm
(Fig. 3). subjective
Comment: The curvature in this term is restricted to the
phalanges and does not refer to deviation at the MCPJ/MTPJ
(see Radial deviation of the fingers). Typically involves an abnor-
mally shaped middle phalanx, but this is not obligate. The identity
of the nger/toe should be specied and the directionality of the
deviation. This nding is most common in F5, and is almost always
radial, but can be seen in any digit and can be in either direction. A
similar effect can be created by radial angulation within the distal
phalanx with epiphyseal thickening, which is called Kirner defor-
mity or dystelephalangy [Ozonoff, 1992].
Replaces: Incurved nger
Clubbing
Denition: Broadening of the soft tissues (non-edematous swelling
of soft tissues) of the digital tips in all dimensions associated with an
increased longitudinal and lateral curvature of the nails (Fig. 4).
subjective
Comment: This denition does not use specication of nail plate
angles for several reasons. First, there is no agreement on which
angle should be measured. Second, there are no known data to
FIG. 1. Adactyly of the feet, bilateral.
FIG. 2. Camptodactyly of F45, bilateral.
FIG. 3. Clinodactyly, radial, F5, bilateral. This person also
has Short finger, F5, bilateral. See also Figures 13 and 20.
FIG. 4. Clubbing. Note that the clubbing is best viewed
laterally (e.g., the thumb) whereas it is difficult to
appreciate in the other digits viewed dorsally. See also
Figures 5 and 63.
BIESECKER ET AL. 95
establish the range of normality. Third, clinicians rarely perform
such measurements. Clubbed ngers are often described as resem-
bling the end of drumsticks. The affected digits should be specied
as described in the introductory comments. If no subtype identier
is specied, it is assumed that all digits are involved. Although
increased soft tissue is the sole or major component of clubbing,
some cases may be associated with bone spurs or modest over-
growth of the distal phalanx. As this is not relevant to the clinical
(non-radiographic) assessment of clubbing, it is not specied in the
denition of this term.
Clubhand: See Hand, radial deviation of; Hand, ulnar devia-
tion of
Digit: See various terms under ‘‘finger’’ or ‘‘toe’’ instead of digit
Digit Pad, Prominent
Denition: A soft tissue prominence of the ventral aspects of the
ngertips or toe tips (Fig. 5). subjective
Comment: The prominence of the nger or toe pads varies
throughout life, being greater in neonates and dependent on the
state of hydration. This term should not be used if the digit has
clubbing. Note that the synonym ‘‘fetal ngertip pads’’ should not
be interpreted to mean that the prominent pad necessarily was
present in this individual since fetal life. We do not endorse the use
of the term ‘‘Persistent fetal pads’’ as this term implies knowledge of
the natural history of this nding, which may or may not be known.
Synonym: Fetal nger/toe tip pads; Fetal nger/toe tip pads
Replaces: Persistent fetal pads
Digital Constriction Ring
Denition: A narrow segment of signicantly reduced circumfer-
ence of a digit (Fig. 6). subjective
Comment: The description should specify the hand and digit
that is affected and the approximate location of the band relative to
the phalanges. It may be described as partial, if it does not involve
the entire circumference of the digit.
Replaces: Amniotic bands
Ectrodactyly: See Foot, split; Hand, split
Fetal ngertip pads: See Digit pad, prominent
Finger, Absent
Denition: The absence of all phalanges of a digit of the hand and
the associated soft tissues (Fig. 7). objective
Comment: This term does not require absence of the metacarpal.
The affected digits should be specied. This denition excludes
Partial absence of the nger. Note that it can be challenging to
number the missing digit if it is a central digit that is missing. In
these cases, it is appropriate to modify the term by adding the phrase
‘‘non-thumb.’’ In contrast, it will be obvious that the thumb is
present or absent. It may also be difcult to distinguish an absent
nger from two digits with an extreme degree of osseous and
cutaneous syndactyly. If a patient is missing all digits of a limb,
the term Adactyly should be used. The term oligodactyly may be
used as a synonym, but only in situations where the missing digit is
not specied. For example, to state that a patient has Oligodactyly
F5 is awkward because the oligodactyly refers to the digits that are
present and the F5 refers to the digit that is absent, which could
become confusing with higher order deciencies. If a digit that
cannot be identied is missing, the term can be modied with a
cardinal number, for example, ‘‘Absent ngers, two.’’
Replaces: Hypodactyly
Synonym: Oligodactyly
FIG. 5. Prominent digit pads, right hand, F3,4. Note that this
patient also has Clubbing and a Single transverse palmar
crease.
FIG. 6. Digital constriction rings, left hand, F15, near MCPJ.
FIG. 7. Finger, absent, right hand. Note here that the
identity of the missing digit is not specied, as there are
no clinical data to allow this to be determined. See also
Figure 68.
96 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Finger, Broad
Denition: Increased width of a non-thumb digit of the hand
(Fig. 8). subjective
Comment: Note that the girth may be increased in a broad nger,
but this must be distinguished from Macrodactyly, because there
the length is also increased. This distinction can be subtle. This term
should not be used when the increased width is limited to the distal
phalanges, instead use Broad ngertips. The affected digit should be
specied by the numbering scheme in the introduction. This term is
not used for the rst digit, see Broad thumbs. When a thumb and
one or more ngers are affected, it may be more economical to
specify ‘‘Broad ngers, F15’’ instead of separately specifying
‘‘Broad thumb’’ and ‘‘Broad ngers F25.’’
Synonym: Wide ngers
Replaces: Pachydactyly; Thick ngers
Fingers, Cutaneous Syndactyly of
Denition: A soft tissue continuity in the A/P axis between two
ngers that extends distally to at least the level of the PIPJ (Fig. 9).
objective OR
A soft tissue continuity in the A/P axis between two ngers that
lies signicantly distal to the exion crease that overlies the meta-
carpophalangeal joint of the adjacent ngers. subjective
Comment: We have set an arguably arbitrary threshold to
distinguish the objective from the subjective nding. While severe
degrees of cutaneous syndactyly are clearly objective, more subtle
degrees are subjective. We set this threshold to distinguish these two
situations. The digits (or parts of) are joined together by tissue that
is not normally present between the digits at that point in the P/D
axis. A modier of ‘‘complete’’ may be used if the cutaneous
syndactyly extends to the distal end of the nail bed of the digits.
The affected digits should be specied. Note that the unqualied
term ‘‘syndactyly’’ is no longer allowed as it is unclear whether this
refers to bony or cutaneous syndactyly.
Replaces: Syndactyly (without adjective); Zygodactyly
Finger, hypoplastic: See Finger, small
Finger, incurved: See Clinodactyly
Fingers, Long
Denition: The middle nger is more than 2 SD above the mean for
newborns 2741 weeks EGA or above the 97th centile for children
from birth to 16 years of age AND the ve digits retain their normal
length proportions relative to each other (i.e., it is not the case that
the middle nger is the only lengthened digit) (Fig. 10). subjective
OR
Fingers that appear disproportionately long compared to the
palm of the hand. subjective
Comment: The rst denition is recognized to be problematic,
because it implies that the other ngers are all as relatively long as is
the middle nger. As the determination of the proportionality of the
other four digits is clearly subjective, the term must be regarded as
subjective. The term arachnodactyly has been abandoned as it is
bundled (narrow and long digits) and is sometimes used for only
narrow or only long digits. The term ‘‘long hand’’ should not be
FIG. 8. Broad ngers, right hand. Appreciate that the
dorsalventral dimension of these digits is not increased,
whereas the lateral (proximo-distal) dimension is
increased. See also Figure 99.
FIG. 9. A: Cutaneous syndactyly of F25, left hand,
complete. Note that this patient also has a Broad thumb,
and Postaxial polydactyly of the hand, type B and Fused
nails F25. B: This patient has Cutaneous syndactyly of
F24, partial. See also Figure 14.
BIESECKER ET AL. 97
used, as it is a bundled denition of two readily separable terms,
Long ngers, and Long palm. If only a subset of the digits of a limb is
lengthened, the affected digits should be specied.
Replaces: Arachnodactyly
Finger, narrow: See Finger, slender
Fingers, Overlapping
Denition:Anger resting on the dorsal surface of an adjacent digit
when the hand is at rest (Fig. 11). objective
Comment: This descriptor is ordered depending on which digits
are involved (see gure legend for examples). The affected digits
should be specied. The ordering of the numbers species which
digit is dorsal, that is, with dorsum of the hand facing upward
the digit on top is/are recorded rst separated by a comma from the
digit that is/are overlapped. Fingers that are laterally deviated, but
do not rest on top of adjacent ngers should be coded as
Clinodactyly.
Finger, Partial Absence of
Denition: The absence of a phalangeal segment of a nger
(Fig. 12). objective
Comment: The part that is absent may be specied. The ‘‘distal’’
modier species the loss of the distal phalanx; clinically this is
dened by the absence of the nail. The ‘‘proximal’’ modier
species the loss of the proximal or middle phalanx with the nail
still present and/or the radiographic nding of a remaining phalanx
that is similar to a distal phalanx. It may be difcult to determine
which phalanx is absent without X-rays and even then, there are
circumstances where the missing bone may not be exactly identied
(note that no attempt is made to distinguish missing middle from
proximal phalanges). In this situation the location adjective will
have to be removed. This nding is distinct from Short ngers.
Replaces: Hypophalangy
Finger, Radial Deviation of
Denition: Angulation of a digit toward the anterior axis (radial
side) of the limb (Fig. 13). subjective
Comment: The deviation is at the MCPJ. The affected digits
should be specied. This nding is distinct from Clinodactyly.
FIG. 10. Long ngers, right hand.
FIG. 11. A: Overlapping ngers, right hand, F54, F56. Note
that this patient also has Mesoaxial polydactyly and
Postaxial polydactyly, type B.B:Overlapping ngers, right
hand, F23, F54. See also Figures 37, 45, and 58A.
FIG. 12. Partial absence of ngers, left hand, F25,
proximal. Note that this patientalsohasSmall nails, F15.
98 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Finger, Short
Denition: The middle nger is more than 2 SD below the mean for
newborns 2741 weeks EGA or below the 3rd centile for children
from birth to 16 years of age AND the ve digits retain their normal
length proportions relative to each (i.e., it is not the case that the
middle nger is the only shortened digit) (Fig. 14). subjective OR
Fingers that appear disproportionately short compared to the
hand. subjective
Comment: This is an acknowledged bundled term as the deni-
tion in most anthropometric sources assumes that the other ngers
are all as relatively short as is the middle nger. As the determination
of the proportionality of the other four digits is clearly subjective,
the term must be regarded as subjective. The Bell classication of
brachydactyly (summarized in Temtamy and McKusick [1969]) is a
complex assessment of hand patterningthat usage of the word
‘‘brachydactyly’’ is independent of the use here. When
‘‘Brachydactyly type x’’ is used, this refers to the Bell classication
patterns. When Brachydactyly of the hand is used, it solely refers to
reduced length of the specied digits. ‘‘Short hand’’ should not be
used as it is a bundled denition of Short ngers and Short palm.If
the distal phalanges are judged to be proportionately shortened, the
additional term of Short distal phalanges of the ngers should not
be used. If the digit is short overall and the distal phalanx is
disproportionately shorter than are the nger overall, then both
terms should be used.
Synonym: Brachydactyly of the hand
Finger, Short Distal Phalanx of
Denition: Short distance from the end of the nger to the most
distal interphalangeal crease or DIPJ exion point (Fig. 15).
subjective
Comment: This term differs from Partial absence of the nger
because in that term, the phalanx must be missing, whereas in this
term it may be small, but present. Distal phalangeal lengths can be
assessed subjectively by comparing the digit segment to the rest of
the digit, to other normal digits in the patient, or to typical patients
of the same age or build. Regarding the subjective denition, for
individuals who do not have exion creases, one may determine this
by exing the DIPJ and estimating the length of the terminal
segment of the digit. Alternatively, one may be able to palpate the
joint.
Synonym: Brachytelephalangy
Replaces: Short terminal phalanges; Short terminal nger
Finger, Slender
Denition: Digits are disproportionately narrow (reduced girth)
for the hand/foot size or build of the individual (Fig. 16). subjective
Comment: The affected digits should be specied as described.
The assessment of this nding is difcult when the digits are long.
The bundled and pejorative term ‘‘arachnodactyly’’ is replaced
by the separate descriptors Long nger and Slender nger.
Synonym: Narrow digits; Narrow ngers
Replaces: Thin digits; Arachnodactyly
FIG. 13. Radial deviation of the nger, left hand, F2. Note
that this patient also has Clinodactyly, F2, radial and that
these two ndings are distinct. See also Figure 47.
FIG. 14. Short ngers. See also Figures 3, 47, 69, and 99.
Note that this patient also has Short palms and cutaneous
syndactyly of F4,5, right hand.
FIG. 15. Short distal phalanx of the nger, left hand, F1. Note
that this patient also has a Short nail, F1. See also
Figure 60A.
BIESECKER ET AL. 99
Finger, Small
Denition: Signicant reduction in both length and girth of the
nger compared to the contralateral nger, or alternatively, com-
pared to a typical nger size for an age-matched individual (Fig. 17).
subjective
Comment: This is a bundled term, comprising Short nger and
Slender digit, but it is so widely used that it is included. This term is
only used if the nger has the normal number of phalangeal
segments. An appropriate alternative term for the rst digit is
Small thumb, when it is the only digit affected. When a thumb
and one or more ngers are affected, it may be more economical to
specify ‘‘Small ngers, F15’’ instead of separately specifying ‘‘Small
thumb’’ and ‘‘Small ngers F25.’’
Replaces: Underdeveloped nger; Hypoplastic nger
Fingers, Splayed
Denition: Divergence of digits along the A/P axis (in the plane of
the palm) (Fig. 18). subjective
Comment: This may be associated with Macrodactyly, but this
should be assessed and coded separately. The affected digits should
be specied.
Synonym: Spreading of the ngers
Fingers, spreading of: See Fingers, splayed
Finger, Tapered
Denition: The gradual reduction in girth of the digit from
proximal to distal (Fig. 19). subjective
Comment: If the digits are not uniformly affected, the affected
ngers should be specied. If not specied, it refers to all the digits of
the hand.
FIG. 16. Slender ngers, right hand, F25. Note that only
some of the digits are clearly shown in this gure.
FIG. 17. Fingers, small, left hand, F3,4. This patient also has
Deep palmar creases.
FIG. 18. Splayed ngers, left hand, F23, F34. Note that this
patient also has Macrodactyly F24.
FIG. 19. A: Tapered nger, left hand, F4.B:Tapered ngers,
right hand, F25. See also Figures 42, 44, and 93.
100 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Finger, thick: See Finger, broad
Finger, thin: See Finger, slender
Finger, Ulnar Deviation of
Denition: Angulation of the digit towards the posterior or post-
axial axis (ulnar) of the limb (Fig. 20). subjective
Comment: The deviation is at the MCPJ. The affected digits
should be specied. This nding is independent of Clinodactyly.
Finger, underdeveloped: See Finger, small
Finger, wide: See Finger, broad
Finger-like thumb: See Thumb, triphalangeal
Fingertip, Broad
Denition: Increased width of the distal segment of a nger
(Fig. 21). subjective
Comment: This term should be reserved for use when the distal
digit is signicantly broader than the middle part. It should not be
used if the digit has Clubbing or Macrodactyly or if the entire nger
is broad; instead use Finger, broad.
Synonym: Wide ngertips
Replaces: Spatulate ngertips
Fingertip, spatulate: See Fingertip, broad
Fingertip, wide: See Fingertip, broad
Fingertip pads, fetal: See Digit, prominent pad
Foot, Absent
Denition: The total absence of the foot, with no bony elements
distal to the tibia or bula (Fig. 22). objective
Comment: See Foot, partial absence of, for a related denition.
Synonym: Apodia
Foot, brachydactyly of: See Toe, short
Foot, Broad
Denition: A foot for which the measured width is above the 95th
centile for age (Fig. 23). objective OR
A foot that appears disproportionately wide for its length.
subjective
Comment: Note that the normative data [Malina et al., 1973;
Hall et al., 2007] only include 416 year olds. Since foot width is still
increasing at the 16-year-old age point on the graphs, extrapolation
is not recommended. Therefore, persons more than 16 years of age
or less than 4 years of age can only be assessed subjectively (until
appropriate norms are identied or generated). The Hall et al.
[2007] handbook (pp. 238239) states that foot width should be
measured from the medial aspect of the rst MTPJ to the lateral
aspect of the fth MTPJ. The subjective denition should be used
with caution in patients with Short feet. In persons with polydactyly
that includes a supernumerary metatarsal, the measurement de-
nition from Hall et al. [2007] would need to be modied to account
for the supernumerary digit (i.e., if the patient had postaxial
polydactyly, measure from the sixth MTPJ). It may be argued that
FIG. 20. Ulnar deviation of nger, right hand, F4. Note that
this patient also has Clinodactyly of F4, ulnar. Note that
his middle nger manifests Clinodactyly radial, F3, but
that this nger is not deviated, demonstrating the
distinction of these two features. See also Figure 45.
FIG. 21. A: Broad ngertip, right hand, F1. Note how the digit
widens at the IPJ. B: Broad ngertips, left hand, F3,4. See
also Figure 93.
BIESECKER ET AL. 101
this is double counting polydactyly as a wide foot, as the norms are
derived from those with pentadactylous limbs.
Synonym: Wide foot
Foot, cleft: See Foot, split
Foot, Long
Denition: Foot length more than 2 SD above the mean for a
newborn of 2741 weeks gestation (Fig. 24). objective OR
Foot length above the 97th centile for individuals from birth to 16
years of age objective OR
A foot that appears longer than expected for age. subjective
Comment: Note that for females over the age of 16 years, the
curves are essentially at by 15 years of age, so the 16-year-old
norms and distribution can be used for older individuals [Anderson
et al., 1956; Hall et al., 2007]. However, the male norms still have
signicant growth at 16 years, where the graph ends. Therefore, only
subjective assessments can be made for males over the age of
16 years. For infants, the norms are specied in SD, per the primary
source [Merlob et al., 1984]. Because of the wide range of normal for
foot measurements, it may be hard to discriminate a long foot of
normal width from that of a narrow foot of normal length, thus the
subjective denition is substantially inferior. If the toes are also
long, that should be coded separately.
Foot, Narrow
Denition: A foot for which the measured width is below the
5th centile for age (Fig. 25). objective OR
A foot that appears disproportionately narrow for its length.
subjective
Comment: The normative data [Hall et al., 2007] only include
416 year olds. Since the foot width is still increasing at the 16 year
old age point on the graphs, extrapolation is not recommended.
Therefore, persons more than 16 years or less than 4 years of age can
only be assessed subjectively (until appropriate norms are identied
or generated). Foot width should be measured from the medial
aspect of the rst MTPJ to the lateral aspect of the fth MTPJ [Hall
et al., 2007]. It does not seem sensible to apply this term to
individuals with polydactyly that includes a duplicated metatarsal.
Foot, Osseous Syndactyly of
Denition: Lateral (A/P) fusion of the digits (phalanges and/or
metatarsals) by hard tissue (cartilage and/or bone) (Fig. 26).
objective
Comment: Metatarsal syndactyly can be demonstrated by the
inability to independently manipulate the two metatarsals
(see Polydactyly, mesoaxial for a description of this maneuver)
FIG. 22. Absent foot, right. Note that thisis the samepatient
as is shown in Figure 27. One limb has partial absence of
the foot and the other complete.
FIG. 23. Broad foot, left. In this example, the forefoot
appears more broad than does the midfoot, but this
distinction is not noted in the nomenclature.
FIG. 24. Long feet. Note thatthis patientalso has Long toes.
102 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
or the continuity of two metatarsals is demonstrated [Biesecker,
2007]. The description should include the bones that are fused.
Osseous syndactyly is distinct from Symphalangism, where the
phalanges are fused at the joint longitudinally (P/D axis). The exact
nature of the bony anomaly may not be denable without X-ray
evidence. Note that the unqualied term ‘‘syndactyly’’ is no longer
allowed as it is unclear whether this refers to bony or cutaneous
syndactyly.
Replaces: Syndactyly (without adjective)
Foot, Partial Absence of
Denition: An incomplete absence of the foot, with no bony
elements distal to the tarsals, but with preservation of some or all
of the tarsals (Fig. 27). objective
Comment: See Foot, absent for a related term.
Foot, Postaxial Polydactyly of
Denition: Presence of a supernumerary digit that is not a hallux
(Fig. 28). objective
Comment: Although it is appealing to believe in many cases that
the supernumerary (non-hallux) digit is the most bular, there may
be no evidence for this. When the digit is de minimus, this seems
reasonable by parsimony. When it is fully formed, associated with a
supernumerary metatarsal, and fully functional, it may be impos-
sible to determine which toe is supernumerary. Nevertheless, the
designation as postaxial is reasonable given the tradition of this
designation. Postaxial polydactyly has been divided into two types:
A (a fully formed digit) and B (digitus minimus, or a pedunculated,
non-articulating, non-functional appendage). We recognize these
subtypes but note that post-axial polydactyly actually represents a
spectrum from type A to type B. When the type is indeterminate, no
subtype is specied. The term uses the word ‘‘postaxial’’ instead of
the embryologic ‘‘posterior’’ because the former is established in
clinical medicine.
Synonym: Posterior polydactyly
Replaces: Posterior duplication of the limb/foot; bular
polydactyly
FIG. 25. Narrow foot, left.
FIG. 26. Osseous syndactyly of the foot. This gure shows
the maneuver used to detect this nding. The abnormal
nding is not shown. The examiner grasps two adjacent
metatarsal and alternately moves them to determine if
they are fused or independent.
FIG. 27. Foot, partial absence of, left. Note that this is the
same patient as is shown in Figure 22. One limb has
complete absence of the foot and the other partial.
BIESECKER ET AL. 103
Foot, Preaxial Polydactyly of
Denition: Duplication of all or part of the rst ray (Fig. 29).
objective
Comment: There is a wide spectrum of this malformation. The
mild end of the spectrum is a bid (not cleft) nail or a distal phalanx
of the hallux with a central lacuna or bid tip. Broadened halluces
without a recognizable anterior/posterior cleft should be coded as
Broad hallux. Note that toe number may be affected by the nding
of preaxial polydactyly. See the introductory comments for guid-
ance on digit numbering. It is optional to modify the term by adding
‘‘partial’’ to a duplicated hallux that involves less than the entire ray
(metatarsal and both phalanges) and ‘‘complete’’ for a digit that has
complete duplication of all three bones.
Synonym: Anterior polydactyly
Replaces: Anterior duplication of the limb; Tibial polydactyly
Foot, Rocker Bottom
Denition: The presence of both a ‘‘prominent heel’’ and a ‘‘convex
contour of the sole’’ (Fig. 30). subjective
Comment: The term is a bundled denition but is in common
usage. For that reason, it was included by consensus of the group.
Foot, Short
Denition: A measured foot length that is more than 2 SD below the
mean for a newborn of 2741 weeks gestation (Fig. 31). objective OR
A foot that is less than the 3rd centile for individuals from birth to
16 years of age. objective OR
A foot that appears disproportionately short. subjective
Comment: Note that for females over the age of 16 years, the
curves are essentially at by 15 years of age, so the 16-year-old
norms and distribution can be used for older individuals [Anderson
et al., 1956; Hall et al., 2007]. However, the male norms still show
signicant growth at 16 years, where the graph ends. Therefore, only
subjective assessments can be made for older males. For infants, the
norms are specied in SD, per the primary source [Merlob et al.,
1984]. Foot length includes the relatively long calcaneus and tarsal
bones as well as the metatarsals and rst toe, and so the hand and
foot measurements may reect different growth abnormalities.
Foot length should be interpreted with caution if the individual
has either Pes cavus or Pes planus.
FIG. 29. A: Preaxial polydactyly of the right foot. Note that
this duplication is nearly complete. B: Preaxial
polydactyly of the right foot. This patient has the same
nding, but the duplicated digits are more separated than
in Figure 29A.
FIG. 28. Postaxial polydactyly of the left foot. Note that this
patient also has Small nails.
FIG. 30. Rocker bottom foot, left.
FIG. 31. Short feet.
104 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Foot, Split
Denition: Longitudinal deciency of a digital ray of the foot
except rays 1 or 5 (Fig. 32). subjective
Comment: The threshold for this deciency should be that all of
the phalanges in the ray are absent and at least part of the metatarsal.
If just the phalanges that are missing, this should be coded as Absent
toe. The absence of a central ray or rays frequently yields a cleft
appearance of the foot. This term is preferred to ‘‘ectrodactyly of the
foot’’ as this has been used (more appropriately) for various forms
of phalangeal hypoplasia or amputation. ‘‘Lobster claw deformity’’
is neither descriptive nor acceptable. There is wide variation in the
affected feet, but the common factor is the absent central ray,
justifying Split foot as a clinical designation.
Synonym: Cleft foot
Replaces: Ectrodactyly; Lobster claw deformity
Foot, wide: See Foot, broad
Hallux, Absent
Denition: The absence of both phalanges of a hallux and the
associated soft tissues (Fig. 33). objective
Comment: This descriptor does not require absence of the
metatarsal. The denition excludes partial absent hallux. Oligo-
dactyly and hypodactyly are replaced with more specic terms to
allow the distinction of loss of a preaxial digit (thumb or great toe)
from loss of digits 25. When a great toe and one or more other toes
are absent, it may be more economical to specify Absent toes, T13
instead of separately specifying Absent hallux and Absent toes
T23.
Synonym: Absent great toe
Replaces: Hypodactyly; Oligodactyly
Hallux, Broad
Denition: Visible increase in width of the hallux without an
increase in the dorso-ventral dimension (Fig. 34). subjective
Comment: Note that girth may be increased in a broad hallux,
but this must be distinguished from Macrodactyly because there the
length is also increased. This assessment may be difcult when the
hallux is short. Note the separate denition for Broad toes.Whena
great toes and one or more other toes are affected, it may be more
economical to specify Broad toes, T15 instead of separately
specifying Broad hallux and Broad toes T25.
Synonym: Broad great toe
Hammertoe
Denition: Hyperextension of the MTPJ with hyperexion of the
PIPJ (Fig. 35). subjective
FIG. 32. A: Split foot, left.B:Split feet. Note that this patient
has a more severe, deeper notch in the feet than does the
patient in (A). The shape and numbers of other affected
digits is highly variable.
FIG. 33. Absent hallux, right.
FIG. 34. Broad hallux, right. See also Figure 60B.
BIESECKER ET AL. 105
Comment: This term replaces the phrase ‘‘dorsiexed toe’’
as that term is an incomplete description of the abnormality
[Young et al., 2005]. Note that this is not a synonym of
mallet toe.
Replaces: Dorsiexed toe
Hand, Absent
Denition: The total absence of the hand, with no bony elements
distal to the radius or ulna (Fig. 36). objective
Comment: See Hand, partial absence for a related term.
Synonym: Acheiria
Hand, brachydactyly of: See Finger, short
Hand, cleft: See Hand, split
Hand, Clenched
Denition: All digits held completely exed at the metacarpopha-
langeal and interphalangeal joints (Fig. 37). subjective
Comment: Is distinguished from Camptodactyly, as that term
may describe fewer than ve digits of a eudactylous hand and does
not involve the MCPJ. The digits may overlap when they lie exed in
the palm. It is not necessary to specify the overlapping ngers
nding separately.
Hand, long: See Palm, long
Hand, narrow: See Palm, narrow
Hand, Osseous Syndactyly of
Denition: Lateral (A/P) fusion of the digits (phalanges and/or
metacarpals) by hard tissue (cartilage and/or bone) (Fig. 38).
objective
Comment: Metacarpal syndactyly can be demonstrated by either
a maneuver whereby the two metacarpals cannot be independently
manipulated by the examiner (see Mesoaxial polydactyly for a
description of this maneuver). Phalangeal syndactyly (typically seen
in what used to be called a ‘‘mitten hand’’) may be difcult to
demonstrate without X-rays. The description may include the
bones that are fused. Osseous syndactyly is distinct from Sympha-
langy where the phalanges are fused at the joint longitudinally (P/D
axis). See Mesoaxial polydactyly for discussion of the use of this
term with polydactyly.
Replaces: Syndactyly (without adjective)
FIG. 35. Hammertoe, T3, left. See also Figure 57.
FIG. 36. Absent hand, left. Note that this patient also has a
shortened radius and ulna, although that nding is not
required for this nding.
FIG. 37. Clenched hand, right. Note that the left hand does
not warrant the term because not all of the digits are
completely exed at the MCPJ and IPJ. The left hand would
warrant the nding of Overlapping ngers F23, F54, left.
106 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Hand, Postaxial Polydactyly of
Denition: Presence of a supernumerary digit that is not a thumb
(Fig. 39). objective
Comment: Although it is appealing to believe in many cases that
the supernumerary (non-thumb) digit is the most ulnar, there may
be no evidence for this. When the digit is de minimus, this seems
reasonable by parsimony. When it is fully formed with a supernu-
merary metacarpal and functional, it may be impossible to deter-
mine which of the ngers is supernumerary. Nevertheless, the
designation as postaxial is reasonable given the tradition of this
designation. Postaxial polydactyly has been divided into two types:
A (a fully formed digit) and B (digitus minimus, or a pedunculated,
non-articulating, non-functional appendage). We recognize these
subtypes but note that post-axial polydactyly actually represents a
spectrum from type A to type B. When the type is indeterminate, no
subtype is specied.
Synonym: Posterior polydactyly
Replaces: Ulnar polydactyly; Posterior duplication of the limb/
hand
Hand, Preaxial Polydactyly of
Denition: Duplication of all or part of the rst ray (Fig. 40).
objective
Comment: There is a wide spectrum of this malformation. The
mild end of the spectrum is a bid (not cleft) nail or a distal phalanx
of the thumb with a central lacuna or bid tip. Broadened thumbs
FIG. 38. Osseous syndactyly of the hand. This gure shows
the maneuver used to detect this nding. The abnormal
nding is not shown. The examiner grasps two adjacent
metacarpals and alternately moves them to determine if
they are fused or independent.
FIG. 39. A: Postaxial polydactyly of the right hand, type A.B:
Postaxial polydactyly of the right hand. Note that this
patient has a digit that is intermediate between type Aand
type B, so that is not specied. See also Figures 49A, 58A,
and 73A. See Figures 9A and 11A for examples of Postaxial
polydactyly, type B.
FIG. 40. A: Preaxial polydactyly of the left hand, partial.B:
Preaxial polydactyly of the right hand.
BIESECKER ET AL. 107
without a recognizable line of anterior/posterior clefting should be
coded as Thumb, broad. Note that nger numbering may be
affected by the nding of preaxial polydactyly. See the introductory
comments for guidance on digit numbering. It is optional to modify
the term by adding ‘‘partial’’ to a duplicated thumb that involves
less than the entire ray (metacarpal and both phalanges) and
‘‘complete’’ for a digit that has complete duplication of all three
bones.
Synonym: Anterior polydactyly
Replaces: Anterior duplication of the limb/hand; Radial
polydactyly
Hand, Radial Deviation of
Denition: Divergence of the longitudinal axis of the hand at the
wrist in a anterior (radial) direction (Fig. 41). subjective
Comment: This nding may be associated with a short or absent
radius, but that is not required and should be coded separately. The
term ‘‘clubhand’’ is replaced because it was felt to be pejorative.
Replaces: Radial clubhand; Clubhand
Hand, short: See Palm, short; Finger, short
Hand, Small
Denition: A normally proportioned hand (i.e., the various ele-
ments of the hand are in proportion to each other) that is overall
small for age or overall body size (Fig. 42). subjective
Comment: This is acknowledged to be a bundled term, but it is
sufciently common that it was felt to be too cumbersome to
describe the component ndings. It is arguably superior to code a
patient as having objectively determined Short ngers, Short
palms, and Narrow palms instead of this bundled term. Note that
there are no objective standards that can be used for this assessment,
only for middle nger and palm length and palm width. The term
acromicria is discouraged because in some denitions, this term
also includes small head or facial features; in others it only includes
the ngers and toes.
Replaces: Acromicria
Hand, Split
Denition: Longitudinal deciency of a digital ray of the hand
except rays 1 or 5 (Fig. 43). subjective
Comment: The threshold for this deciency should be that all of
the phalanges of a central ray (not F1 or F5) are absent and at least
part of the associated metacarpal (if it is just the phalanges that are
missing, this should be coded as Absent nger). The absence of a
central ray or rays frequently yields a cleft appearance of the hand.
This term is preferred to ‘‘ectrodactyly of the hand’’ as this has been
used (more appropriately) for forms of phalangeal hypoplasia or
amputation but it is acknowledged that this is a commonly used
term. ‘‘Lobster claw deformity’’ is neither descriptive nor accept-
able due to its pejorative nature. There is wide variation in the hands
of affected individuals, but the common factor seems to be the
absence of the central ray, justifying the use of Split hand as a clinical
designation.
Synonym: Cleft hand
Replaces: Ectrodactyly; Lobster claw deformity
Hand, Trident
Denition: Splaying of F24 along the A/P axis (in the plane of the
palm) with relatively normal positioning of F1 and F5 (Fig. 44).
subjective
Comment: This term is a subtype of splaying of the digits, but its
diagnostic utility warrants a separate denition. Note is made that
there were a number of different denitions of this term among the
FIG. 41. Radial deviation of the hand, right.
FIG. 42. Small hands. Note that this patient also has
Tapered ngers.
FIG. 43. Split hand, right.
108 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
terminology group members. However, this denition was the
consensus.
Hand, Ulnar Deviation of
Denition: Divergence of the longitudinal axis of the hand at the
wrist in a posterior (ulnar) direction (Fig. 45). subjective
Comment: May be associated with a short or absent ulna, but
that is not required.
Replaces: Ulnar clubhand; Clubhand
Hand, wide: See Hand, broad
Heel, Prominent
Denition: Exaggerated or marked projection of the posterior pole
of the heel (Fig. 46). subjective
Comment: No sensible thresholds or landmarks could be iden-
tied for this nding so the examiners must rely on their experience.
Hypodactyly: See Finger, absent; Hallux, absent; Thumb, absent;
Toe, absent
Hypophalangy: See Finger, partial absence of; Toe, partial
absence of
Hypothenar Eminence, Small
Denition: Reduced muscle mass on the ulnar side of the palm
(Fig. 47). subjective
Comment: The reduced soft tissue is typically abductor digiti
minimi and exor digiti minimi brevis. This may be even more
difcult to discern than is Small thenar eminence, but the same
considerations outlined in that denition apply.
Limb, anterior duplication of: See Foot, preaxial polydactyly of;
Hand, preaxial polydactyly of
Lobster claw deformity: See Foot, split; Hand, split
Macrodactyly
Denition: Signicant increase in the length and girth of most or all
of a digit compared to its contralateral digit (if unaffected) or
compared to what would be expected for age/body build. The
increased girth is accompanied by an increase in the dorso-ventral
dimension AND the lateral dimension of the digit (Fig. 48).
subjective
Comment: There are no recognized standards for the girth of
digits and this nding can vary substantially in the population. This
FIG. 44. Trident hand, left. Note that this patient also has
Tapered ngers, but that is not required for the nding.
FIG. 45. Ulnar deviation of the right hand. Note that this
patient also has Ulnar deviation of the ngers, F23 and
Overlapping ngers F45.
FIG. 46. Prominent heels.
FIG. 47. Small hypothenar eminence, left hand. Note that
this patient also has Short ngers F25 and Radial
deviation of ngers F23.
BIESECKER ET AL. 109
assessment relies on the judgment of the examiner to recognize
when the difference between the expected and the observed is
signicant. The affected digits should be specied. The denition
does not mandate the component of the increased size (bone,
connective tissue, etc.), but should exclude edema. The require-
ment that the girth is most, or all, of the digit is intended to
distinguish this from broad ngertips. This should be distinguished
from Broad ngers or Broad ngertips as the girth is circumferen-
tial in macrodactyly, which is not the case for broad ngers or broad
ngertips, which are increased only (or predominantly) in their
lateral (A/P) width.
Replaces: Megalodactyly; Pachydactyly
Megalodactyly: See Macrodactyly
Metacarpal, Short
Denition: Diminished length of one or more metacarpal bones in
relation to the others of the same hand or to the contralateral
metacarpal (Fig. 49). subjective
Comment: Short metacarpals can involve any of the metacarpal
bones, and the affected ray should be specied. The assessment of
isolated short metacarpal can be made by viewing the dorsum
of the hand when clenched. Note that if metacarpals F25are
affected, the correct term is Short palm. The affected digits should
be specied.
Metatarsal, Short
Denition: Diminished length of a metatarsal, with resultant
proximal displacement of the associated toe (Fig. 50). subjective
Comment: This is a subjective assessment and one generally
compares the position of the MTP joint to that of the contralateral
digit or the putatively shortened ray in proportion to the other rays.
The affected digits should be specied.
FIG. 48. A: Macrodactyly of F2-3, left hand. Note that this
person also has Clinodactyly, but that nding should be
coded separately. B: Macrodactyly of T1-2, right foot. This
patient also has Widely spaced toes. See also Figures 18,
81, and 83.
FIG. 49. A: Short metacarpal, F5, left hand. Note that
this patient also has a Postaxial polydactyly.B:Short
metacarpals, F34, left hand F4, right hand. Note that
this patients hands are shown in dorsal view, with the
ngers exed, which can facilitate the recognition of this
nding.
110 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Metatarsus Adductus
Denition: The metatarsals are deviated medially (tibially)
(Fig. 51). subjective
Comment: This is considered subjective, as there is no objective
threshold for the nding.
Oligodactyly: See Finger, absent; Toe, absent
Pachydactyly: See Finger, broad; Macrodactyly
Palm, Broad
Denition: For children from birth to 4 years of age the palm width
is more than 2 SD above the mean; for children from 4 to 16 years of
age the palm width is above the 95th centile (Fig. 52). objective OR
The width of the palm appears disproportionately wide for the
length. subjective
Comment: Hand width is measured across the palm at the level
of the MCPJ (radial aspect of the second MCPJ to the ulnar aspect of
the fth MCPJ) [Hall et al., 2007]. Caution is advised with the
subjective assessment as short metacarpals can mimic a broad palm.
In persons with polydactyly that includes a supernumerary meta-
carpal, that should be separately coded and the measurement
technique from Hall et al. [2007] would need to be modied to
account for the supernumerary digit (i.e., with postaxial polydac-
tyly, measure to the sixth MCPJ).
Synonym: Wide palm
Palm, Long
Denition: For children from birth to 16 years of age the length of
the palm is more than the 97th centile (Fig. 53). objective OR
The length of the palm appears relatively long compared to the
nger length or the limb length. subjective
Comment: Palm length standards are found in Feingold and
Bossert [1974] and Hall et al. [2007]. The palm is measured from the
distal wrist exion crease to the exion crease of the F3 MCPJ. The
term ‘‘long hand’’ should not be used as it is a bundled denition of
FIG. 50. Short metatarsals, T3,4, bilateral.
FIG. 51. Metatarsus adductus, left. Note that this patient
also has a Sandal gap.
FIG. 52. Broad palm, left. Note that this patient had normal
palm length, so that this is not an example of a short palm
with only an apparently broad palm.
FIG. 53. Long palms. Note that this patient had normal palm
width, so that this is not an example of a narrow palm with
only an apparently broad palm. Note that this image
illustrates a number of other features, which are not
delineated. See also Figures 63 and 85.
BIESECKER ET AL. 111
two readily separable terms, Long ngers (which, as noted above,
can itself be a bundled term) and Long palm.
Replaces: Long hand
Palm, Narrow
Denition: For children from birth to 4 years of age, the palm width
is more than 2 SD below the mean; for children from 4 to 16 years of
age the palm width is below the 5th centile (Fig. 54). objective OR
The width of the palm appears disproportionately narrow for its
length. subjective
Comment: Palm width is measured across the palm at the level of
the MCPJ (radial aspect of the F2 MCPJ to the ulnar aspect of the F5
MCPJ). Norms are specied in Hall et al. [2007]. Caution is advised
for the subjective assessment as the breadth may be in the normal
range with disproportionately increased length, which appears
narrow. This nding may be associated with elongated/slender
limbs in general, but that nding does not bear on the coding of this
feature. Proximal narrowing may indicate small thenar or hypoth-
enar eminences. This term replaces ‘‘narrow hands’’ as that term
may leave the impression that it includes the thumb, which it
does not.
Replaces: Narrow hand
Palm, Short
Denition: For children from birth to 16 years of age the length of
the palm is less than the 3rd centile (Fig. 55). objective OR
The length of the palm appears relatively small compared to the
nger length or the limb length. subjective
Comment: Palm length is measured as described in Feingold and
Bossert [1974] and Hall et al. [2007]. This term is reserved for
individuals with shortening of all four metacarpals 25. Individuals
with fewer than four shortened metacarpals (in a eudactylous hand,
the metacarpals of F25) should be coded as Short metacarpal. See
the entry for Small hand for a discussion of this nding. ‘‘Short
hand’’ should not be used as it is a bundle of two readily separable
terms, Short ngers (which, as noted above, can itself be a bundled
term) and Short palm.
Replaces: Short hand
Palm, wide: See Palm, broad
Pes Cavus
Denition: The presence of an unusually high plantar arch
(Fig. 56). subjective
Comment: This is a subjective denition for which we could
identify no thresholds or standards. Examiners must rely on their
experience to make this assessment.
Replaces: High arch
Pes Planus
Denition: A foot where the arch is in contact with the ground or
oor when the individual is standing (Fig. 57). objective OR
In a patient lying supine, a foot where the arch is in contact with
the surface of a at board pressed against the sole of the foot by the
examiner with a pressure similar to that expected from weight
bearing. objective OR
FIG. 54. Narrow palms. Note that this patient had normal
palm width, so that this is not an example of a long palms
with only apparently narrow palms.
FIG. 55. Short palms. Note that this patient also has Short
ngers. This patient does not warrant a nding of Small
hands, because the ngers are of normal caliber. See also
Figure 14.
FIG. 56. Pes cavus. Note that this patient could also be said
to have pes equinus, but that term is not included in the
current terminology set.
112 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
The height of the arch is reduced. subjective
Comment: The second denition was conceived by this working
group based on a common-sense analysis of how one could
generalize the rst denition to a non-ambulatory individual.
There are no data on this assessment and we invite feedback on
its utility.
Replaces: Dropped arches; Fallen arches
Pollex: See various terms under the heading of ‘‘Thumb’’
Polydactyly, anterior: See Foot, preaxial polydactyly of; Hand,
preaxial polydactyly of
Polydactyly, central: See Polydactyly, mesoaxial
Polydactyly, insertional: See Polydactyly, mesoaxial
Polydactyly, intercalary: See Polydactyly, mesoaxial
Polydactyly, Mesoaxial
Denition: The presence of a supernumerary nger or toe (not a
thumb or hallux) involving the third or fourth metacarpal/tarsal
with associated osseous syndactyly (Fig. 58). objective
Comment: To determine this nding in the hand without using a
radiograph [see Allanson et al., 2009b this issue, for a discussion of
the use of radiographs], the examiner grasps two adjacent meta-
carpals, each with a thumb and index nger on the dorsum and
palmar aspect of the hand and attempts to independently maneuver
the metacarpals. If they cannot be independently manipulated,
osseous syndactyly is present [Biesecker, 2007]. Consensus could
not be reached on the utility of the bundled term of Mesoaxial
polydactyly, so it is specied in the terminology for the time being.
It is arguably superior to describe the two separate terms (e.g.,
Osseous syndactyly of F3,4 (metacarpal) and Postaxial polydactyly
of the hand, type A). The term ‘‘insertional polydactyly’’ may be less
desirable because the word ‘‘insertion’’ implies mechanism, which
is unlikely to be an insertion. The utility of this term should be
reviewed over time.
Synonym: Central polydactyly; Intercalary polydactyly
Replaces: Insertional polydactyly
Polydactyly, Mirror Image
Denition: A hand or foot with more than ve digits that has a
recognizable A/P axis of symmetry. The axis can lie within a
normally formed or partially duplicated digit resembling a middle
nger, index nger, thumb, toe, or hallux. Alternatively, the axis can
be in an interdigital space with a anking pair of digits that resemble
a middle nger, index nger, thumb, toe or hallux. The most lateral
digits on each side of the hand typically resemble fth ngers/toes
(Fig. 59). subjective
Comment: This is considered to be a subjective assessment.
Although polydactyly is obviously objective, the assessment of the
FIG. 57. Pes planus, left foot.
FIG. 58. A: Mesoaxial polydactyly of the hand, right. Note
that this patient has heptadactyly, manifesting as well
Postaxial polydactyly, type B. The gure also shows Small
nail, F6 and Overlapping ngers F56. See also Figure 11A.
B: Mesoaxial polydactyly of the right foot. This patient also
has Cutaneous syndactyly of the toes, partial, T23.
FIG. 59. Mirror image polydactyly, right foot. Note that this
patient also has Cutaneous syndactyly of numerous
digits, notable on the right foot.
BIESECKER ET AL. 113
A/P symmetry component is arguably subjective. It may be associ-
ated with a forearm that has two ulnae, but this is not required for
the nding to be made.
Polydactyly, bular: See Foot, postaxial polydactyly of
Polydactyly, posterior: See Foot, postaxial polydactyly of; Hand,
postaxial polydactyly of
Polydactyly, radial: See Hand, preaxial polydactyly of
Posterior duplication: See Foot, postaxial polydactyly of; Hand,
postaxial polydactyly of
Radial clubhand: See Hand, radial deviation of
Ray, Absent
Denition: The absence of all phalanges of a digit and the associated
metacarpal /metatarsal (Fig. 60). objective
Comment: This descriptor requires, in addition to the absence of
the phalanges, absence of the metacarpal or metatarsal. Compare
this to Absent thumb, Absent hallux, Absent toes, and Absent
ngers. In most cases, the absent metacarpal or metatarsal can be
assessed by palpation, but in some cases radiographs may be useful.
This denition excludes Split hand and Split foot. If a patient meets
the denition of either of those terms, they should be used and
Absent ray should not.
Sandal Gap
Denition: A widely spaced gap between the rst toe (the great toe)
and the second toe (Fig. 61). subjective
Comment: The term is a subjective one but should be used when
the gap between the toes is as wide as the second toe is broad.
Sole, Convex Contour of
Denition: The contour of the foot in lateral prole has a convex
shape (Fig. 62). subjective
Comment: This term was established as the convex contour may
occur without the prominent heel, which together comprise the
bundled term Rocker bottom foot.
Streblodactyly: See Camptodactyly
Syndactyly; See Fingers, cutaneous syndactyly of; Toes, cuta-
neous syndactyly of; Foot, osseous syndactyly of; Hand, osseous
syndactyly of
FIG. 60. A: Absent ray, right hand. Note that this patient also
has Short distal phalanges of the ngers and Short nails.
B: Absent ray, left foot. Note that this patient also
manifests a Broad hallux, which should be coded
separately.
FIG. 61. A: Sandal gap, right foot.B:Sandal gaps. See also
Figures 48 and 51.
114 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Thenar Eminence, Small
Denition: Reduced palmar soft tissue mass surrounding the base
of the thumb (Fig. 63). subjective
Comment: The reduced soft tissue is typically abductor pollicis
brevis and exor pollicis brevis muscle bulk. Detection of this
abnormality entails clinical judgment, especially in mild cases. The
bulk of the muscle mass around the base of the thumb is diminished,
and there may be a mild concavity over the volar aspect of the rst
metacarpal. When the deciency is unilateral, comparison between
the two hands will point up the often-subtle change in contour of
the thenar muscles. If the degree of involvement is severe, the palm
may taper in width proximally.
Replaces: Thenar hypoplasia
Terminal phalanx, short: See Finger, short distal phalanx of;
Hallux, short distal phalanx of; Thumb, short distal phalanx of;
Toe, short distal phalanx of
Thenar hypoplasia: See Thenar eminence, small
Thumb abducted: See Thumb, hitchhiker
Thumb, Absent
Denition: The absence of both phalanges of a thumb and the
associated soft tissues (Fig. 64). objective
Comment: This descriptor does not require absence of the
metacarpal. This denition excludes Partial absence of the thumb.
Oligodactyly and hypodactyly have been replaced with more spe-
cic terms to allow the distinction of loss of a thumb from loss of
F25. The term ‘‘oligodactyly’’ is replaced because oligodactyly
refers to the digits that remain, and so ‘‘oligodactyly of the thumb’’
or ‘‘oligodactyly F1’’ is nonsensical.
Replaces: Hypodactyly; Oligodactyly
Thumb, Adducted
Denition: In the resting position, the tip of the thumb is on, or
near, the palm, close to the base of the fourth or fth nger (Fig. 65).
subjective
Comment: The thumb is both exed and adducted. Lesser
degrees of adduction than that specied here may warrant the use
of this term, for example, when the tip of the thumb lies near the
base of F2 or F3.
Thumb, Broad
Denition: Increased thumb width without increased dorso-ven-
tral dimension (Fig. 66). subjective
Comment: There is substantial variability in thumb width and it
may be difcult to determine the threshold for this nding. As it is
commonly bilateral, comparing to the contralateral digit will not be
FIG. 62. Convex contour of the sole right foot. Note the heel
in this patient is not sufciently prominent to warrant the
descriptor of Rocker bottom foot.
FIG. 63. Small Thenar eminence right hand. Note that this
person also has Clubbing (visible in the thumb only). This
patient also has Long palm, right hand.
FIG. 64. Absent thumb, left.
BIESECKER ET AL. 115
helpful. Some have suggested using a denition of thumb width
measured at the IP joint of >1.5X the width of the index nger
measured at the DIPJ, but no data to support this are available. Note
that this term should not be used for thumbs that meet the
denition for Macrodactyly. There is a standard for thumb width
at birth of 9.8 0.5 mm (1 SD) (see Saul et al. [1998], p 45), but this is
not widely used and does not take into account gestational age, or a
body who is small for gestational age. The assessment is difcult
when the thumb is short.
Synonym: Broad pollex; Wide thumb
Thumb, digitalized: See Thumb, triphalangeal
Thumb, Hitchhiker
Denition: With the hand relaxed and the thumb in the plane of the
palm, the axis of the thumb forms an angle 90 degrees with the
long axis of the hand (Fig. 67). objective
Replaces: Abducted thumb
Thumb, Partial Absence of
Denition: The absence of a phalangeal segment of a thumb
(Fig. 68). objective
Comment: The part that is absent may be specied. The ‘‘distal’’
modier species the loss of the distal phalanx; clinically this is
dened by the absence of the nail. The ‘‘proximal’’ modier
species the loss of the proximal phalanx. This nding is distinct
from Short thumb.
Replaces: Hypophalangy
Thumb, Proximal Placement of
Denition: Thumb placement index >0.55 (Fig. 69). objective OR
The base of the thumb appears closer to the wrist than is typical.
subjective.
FIG. 65. Thumb, adducted, right.
FIG. 66. Broad thumbs. See also Figure 9A.
FIG. 67. Hitchhiker thumb, right.
FIG. 68. Thumb, partial absence of, right. Note that this
patient also has Absent ngers, F24, and Absent nger
F5, partial.
116 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Comment: The technique for the thumb placement index is
described in detail [Malina et al., 1973; Hall et al., 2007]. Briey, the
thumb placement index is the distance from the proximal crease of
the index nger to the angle of the rst interdigital space divided by
the distance from the proximal crease of the index nger to the wrist
exion crease at the base of the thumb. This term should not be used
with Preaxial polydactyly.
Thumb, Triphalangeal
Denition: A thumb with three phalanges in a single, proximo-
distal axis (Fig. 70). objective
Comment: The requirement for a single PD axis relates to the
issue that partial forms of Preaxial polydactyly may comprise a
partially duplicated thumb with two distal phalanges and a single
proximal phalanx. That nding is instead coded as a mild form of
thumb polydactyly. Note that this nding can be readily assessed by
examination and/or physical manipulation of the thumb.
Replaces: Digitalized thumb; Finger-like thumb
Tibial polydactyly: See Foot, preaxial polydactyly of
Toe, Absent
Denition: The absence of all phalanges of a non-hallux digit of the
foot and the associated soft tissues (Fig. 71). objective
Comment: Note that this descriptor does not require absence of
the metatarsal. The affected digits should be specied, although this
may be difcult. In the latter case, the specied term should be
‘‘Absent toe, right foot’’ (with the identity of the missing toe not
specied). This denition excludes Partial absence of the toe. This
absent toe denition excludes Absent hallux because it is usually
obvious if the missing digit is a hallux. It may be difcult to
distinguish an absent toe from two digits with an extreme degree
of osseous and cutaneous syndactyly. If all digits are missing, the
term Adactyly should be used. The term Oligodactyly may be used
as a synonym, but only in situations where the missing digit is not
specied. For example, to state that a patient has Oligodactyly F5 is
incorrect because the oligodactyly refers to the digits that are
present and the F5 refers to the digit that is absent. This is awkward
and could be confused with higher order deciencies.
Replaces: Hypodactyly
Synonym: Oligodactyly
Toe, Broad
Denition: Visible increase in width of the non-hallux digit without
an increase in the dorso-ventral dimension (Fig. 72). subjective
Comment: Note that the girth may be increased in a broad toe,
but this must be distinguished from Macrodactyly because in
Macrodactyly the length is increased as well. The affected digit
should be specied. Note that this assessment may be difcult when
the toes are short. This term is not used for the rst digit, see Broad
hallux. If all ve digits are broad, both terms should be used for that
patient.
Toes, Cutaneous Syndactyly of
Denition: A soft tissue continuity in the A/P axis between adjacent
foot digits that involves at least half of the P/D length of one of the
two involved digits (Fig. 73). objective OR
A soft tissue continuity in the A/P axis between two digits of the
foot that does not meet the prior objective criteria. subjective
Comment: The digits (or part of) are joined together by soft
tissue that is not normally present between the digits at that point in
the P/D axis. The denition of toe syndactyly is subtly different from
FIG. 69. Thumb, proximal placement of, right hand.Note that
this patient also has Short nger, F2.
FIG. 70. Triphalangeal thumb, right.
FIG. 71. Absent toe, right.
BIESECKER ET AL. 117
that of the hand. The denition used for the hands was thought to be
difcult with toes, as the phalangeal lengths are small and an
assessment of the degree of syndactyly is impractical. A modier
of ‘‘complete’’ may be used if the syndactyly extends to the distal end
of the nail bed. The affected digits should be specied.
Replaces: Syndactyly (without specication); Zygodactyly
Toe, great; all terms referring to the rst toe are listed under
Hallux or Toe
Toe, hypoplastic: See Toe, small
Toe, Long
Denition: Digits that appear disproportionately long compared to
the foot (Fig. 74). subjective
Comment: This nding must be distinguished from digits that
are thin but of normal length and that of a short mid and hind foot
with normal digit lengths. The affected digits should be specied.
The term arachnodactyly should be discontinued as it may be
considered disparaging to liken a patients digits to that of a spider.
If only a subset of the digits of a limb is lengthened, the affected
digits should be specied.
Replaces: Arachnodactyly
Toe, narrow: See Toe, slender
Toes, Overlapping
Denition: Describes a foot digit resting on the dorsal surface of an
adjacent digit when the foot is at rest (Fig. 75). objective
Comment: This descriptor is ordered depending on which toes
are involved. The overriding toe is labeled, as specied in the
introduction (item 3): for example, T3,4. The ordering of the
FIG. 72. Toe, broad, left, T1. See also Figures 92, 94,
and 101.
FIG. 73. A: Cutaneous syndactyly of the toes, complete,
TT16, left. See also Figures 58B, 59, 78, 92, 94, and 101.
Note that his patient also has Preaxial polydactyly of the
foot, left.B:Cutaneous syndactyly of the toes, T24,
bilateral. As specied in the denitions, this nding is
objective if the syndactyly extends more than half the
proximo-distal length of the digits.
FIG. 74. Long toes, left foot. See also Figures 24 and 79.
118 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
numbers species which toe is dorsal, that is, with dorsum of the
foot facing upward the toe on top is/are recorded rst separated by a
comma from the digit that is/are overlapped. Toes that are laterally
deviated, but do not rest on top of adjacent toes should be coded as
Clinodactyly.
Toe, Partial Absence of
Denition: The absence of a phalangeal segment of a toe or hallux
(Fig. 76). objective
Comment: The part that is absent may be specied. The ‘‘distal’’
modier species the loss of the distal phalanx; clinically this is
dened by the absence of the nail. The ‘‘proximal’’ modier
species the loss of the proximal or middle phalanx with the nail
still present. It may be difcult to know which phalanx is absent
without X-rays and even then, the missing bone may not be
identied (note no attempt is made to distinguish missing middle
from proximal phalanges). In this situation the location adjective
should be removed. Note that this nding is distinct from Short
toes, (which are reduced in length but have the normal number of
phalangeal segments). Partial absence of the hallux is an alternative
term that may be used for the rst toe.
Replaces: Hypophalangy
Toe, Short
Denition: Digits that appear disproportionately short compared
to the foot (Fig. 77). subjective
Comment: This nding must be distinguished from digits that
are of increased girth but of normal length and that of a long mid-
and hind foot with normal digit lengths. The affected digits should
be specied as described in the introductory comments. Note that
we designate brachydactyly as a synonym, but this use of the term is
distinct from the use of the same word in Bells classication (see
Short ngers).
Synonym: Brachydactyly of the foot
Toe, Short Distal Phalanx of
Denition: Short distance from the end of the toe to the most distal
interphalangeal crease or DIPJ exion point (Fig. 78). subjective
Comment: This term differs from Partial absence of the toe
because in that term the phalanx must be missing, whereas here it
may be small, but present. Relative shortening of the distal phalan-
ges of the toes can be harder to assess than in the ngers, as they are
normally quite short. Distal phalangeal lengths can be assessed
subjectively by comparing that digit segment to the rest of the digit,
to other normal digits in that patient, or to typical patients of that
age or build. Although exion creases can be useful in the hand
FIG. 75. Overlapping toes T45, bilateral.
FIG. 76. Toes, partial absence of, right foot, T2,4. Note that
this is the same image as in Figure 82, Toe, tapered.
FIG. 77. Short toes, T15, right foot. Note that this patient
also has Short distal phalanges of toes T2,3.
BIESECKER ET AL. 119
(see Short distal phalanx of the nger), this may not be practical in
the foot. Alternatively, one may be able to palpate the joint.
Synonym: Brachytelephalangy
Replaces: Short terminal phalanx of the hallux
Toe, Slender
Denition: Digits are disproportionately narrow (reduced girth)
for the hand/foot size or build of the individual (Fig. 79). subjective
Comment: The affected digits should be specied. The assess-
ment of this nding is difcult when the digits are long. The bundled
and pejorative term ‘‘arachnodactyly’’ is replaced by the separate
descriptors Long toe and Slender toe.
Synonym: Narrow digit; Narrow toe
Replaces: Thin digits; Arachnodactyly
Toe, Small
Denition: Signicant reduction in both length and girth of the toe
compared to the contralateral toe, or alternatively, compared to a
typical toe size for an age-matched individual (Fig. 80). subjective
Comment: This is an acknowledged bundled term. There are no
standards for this nding, clinical judgment must be used. The
affected toes should be numbered.
Toes, Splayed
Denition: Divergence of digits along the A/P axis (in the plane of
the sole) (Fig. 81). subjective
Comment: This may be associated with Macrodactyly but this
should be recorded separately. The affected digits should be
specied.
Synonym: Spreading of the digits
Toe, Tapered
Denition: The gradual reduction in girth of the digit from
proximal to distal (Fig. 82). subjective
FIG. 78. Short distal phalanges of toes T24, right foot. Note
that this patient also has Cutaneous syndactyly of toes
T23. See also Figure 77.
FIG. 79. Slender toes, T25, right foot. Note that this patient
also has Long toes T15.
FIG. 80. Small toe, T1, left foot. See also Figure 81.
FIG. 81. Splayed toes, T23 right foot, T12, left foot. Note that
this nding differs from Toes, widely spaced, because in
splayed toes the toes have a divergent axis of orientation.
This patient also has Small toe, T1, right and Macrodactyly
of T2,3, right, and T1,2, left.
120 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Comment: If the digits are not uniformly affected, they should be
specied. If not specied, it refers to all the digits of the foot.
Toe, thick: See Toe, broad
Toe, thin: See Toe, slender
Toe, wide: See Toe, broad
Toes, Widely Spaced
Denition: An overall widening of the spaces between the digits
(Fig. 83). subjective
Comment: This description is based on the width of the gap
between the toes. It is usually used when the width of the toes
remains normal rather than to describe a situation where the toes
are thin or narrow. This term should not be used for the situation
where the nding is limited to a gap between T1,2 (see Sandal gap).
Ulnar clubhand: See Hand, ulnar deviation of
Ulnar polydactyly: See Hand, postaxial polydactyly of
Zygodactyly: See Fingers, cutaneous syndactyly of; Toes, cutaneous
syndactyly of
CREASES
See Fig. 84 for a diagram of the three major palmar creases. One end
of the distal transverse crease is on the radial side of the hand
proximal to the base of the index nger or the second interdigital
space and extends toward the ulnar side of the palm. One end of the
proximal transverse crease begins on the radial (anterior) side of the
palm in the rst interdigital space and extends across the palm
towards, but does not typically reach, the ulnar side of the palm.
One end of the thenar crease is typically coincident with the radial
part of the proximal transverse crease and extends proximally
toward the wrist.
Crease, simian: See Palmar crease, single transverse
Palmar Crease, Absent
Denition: The absence of a major crease of the palm (distal
transverse crease, proximal transverse crease, or thenar crease)
(Fig. 85). subjective
Comment: This term is not used to describe the ‘‘missing’’ crease
in the case of a patient with a single transverse palmar crease.
FIG. 82. Toe, tapered, T5.Note that this isthe same image as
in Figure 76, Toe, partial absence.
FIG. 83. Toes, widely spaced, T1,2, T4,5. Note that this
patient also has Macrodactyly of T1,2.
FIG. 84. Normal palmar creases. See text for explanatory
material.
BIESECKER ET AL. 121
Palmar Crease, Bridged
Denition: A crease that connects the proximal and distal trans-
verse palmar creases (Fig. 86). objective
Comment: The crease that connects the two transverse creases
should itself be more in the transverse (antero-posterior) than
longitudinal (proximo-distal) orientation.
Synonym: Transitional palmar crease
Palmar Creases, Decreased
Denition: Poorly dened or shallow palmar creases (Fig. 87).
subjective
Comment: This is a completely subjective term, requiring an
experienced observer to distinguish this nding from common
variation in creases. It refers to an overall diminution of the creases,
not to diminution of a subset of the creases.
Replaces: Smooth palms
Palmar Crease, Deep
Denition: Excessively deep creases of the palm (Fig. 88). subjective
Comment: Like the term Decreased palmar creases, this assess-
ment requires an experienced observer to distinguish this from
common crease variation. One view is that deep creases are those in
which lint could still get stuck, even if the palm is fully opened.
Palmar Crease, Single Transverse
Denition: The distal and proximal transverse palmar creases are
merged into a single transverse palmar crease (Fig. 89). objective
FIG. 85. Palmar creases, absent, left hand. Note that this
patient also has Long palm, left and Single transverse
crease, right hand.
FIG. 86. Bridged palmar crease, right hand.
FIG. 87. Palmar creases, decreased, right hand.
FIG. 88. Palmar creases, deep. See also Figure 17.
FIG. 89. Single transverse palmar crease, right hand. See also
Figures 5 and 85.
122 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Comment: The term ‘‘five nger crease’’ for the proximal
transverse crease is sourced from [Hall et al., 2007]. The subtypes
of single transverse palmar crease are not recognized here [Hook
et al., 1974]. Replaces the term ‘‘Simian crease’’ as that term is
disparaging and less descriptive.
Replaces: Simian crease
Palmar crease, transitional: See Palmar crease, bridged
Palms, smooth: See Palmar creases, decreased
Plantar Crease, Deep Longitudinal
Denition: Narrow, paramedian longitudinal depressions in the
plantar skin of the forefoot (Fig. 90). subjective
Comment: As described for a number of other terms, there are
no thresholds or guides for the clinician to assess this nding.
Instead, the clinician must rely on experience.
Sydney Crease
Denition: Extension of the proximal transverse crease (ve nger
crease) to the ulnar edge of the palm (Fig. 91). objective
Comment: The proximal transverse (ve nger) crease starts on
the radial side of the hand near the base of the index nger and
extends toward the ulnar side of the palm, but does not reach the
ulnar side. In this nding, the crease extends completely to the ulnar
margin of the palm.
NAILS
Brachyonychia: See Short nail
Koilonychia: See Nail, concave
Micronychia: See Nail, small
Nail, Bid
Denition: A digit with two nails, with at least some soft tissue
between them (Fig. 92). subjective
Comment: See the Preaxial polydactyly denition for a related
point on bid nails. The affected digits should be specied. If the
patient has a partially duplicated digit with two completely separate
nails, this term should not be used.
Nail, Concave
Denition: The natural longitudinal (P/D) convex arch is not
present or is inverted (Fig. 93). subjective
Comment: This often results in a saucer- or spoon-shaped nail
and the free edge of the nail is typically everted. The affected digits
should be specied. Note that the bundled term koilonychia is an
abnormal shape of the ngernail where the nail has raised ridges and
is thin and concave.
Replaces: Koilonychia; Spoon shaped nails
Nails, dystrophic: The term ‘‘dystrophic’’ is no longer accepted as a
descriptor for nails with an unusual morphology. The specic
characteristic should be described.
Nails, Fused
Denition: A nail plate that has a longitudinal separation with
partially separated nails, each with a separate lateral radius of
curvature (Fig. 94). subjective
FIG. 90. Deep longitudinal plantar crease, right foot.
FIG. 91. Sydney crease, left hand.
FIG. 92. Nail, bid, T1, left foot. See also Figure 99. Note that
this patient also has a Broad toe, T1 and Cutaneous
syndactyly, partial, T23.
BIESECKER ET AL. 123
Comment: The use of the word ‘‘fused’’ is not meant to imply
that pathogenetically these nails were separate and merged. This is
distinct from a split or cleaved nail, where the two parts of the nails
share the same radius of curvature. The involved digits should be
specied. It may be associated with underlying syndactylous digits,
but these are coded separately.
Nail, hypoplastic: See Nail, small
Nail, Hyperconvex
Denition: When viewed on end (with the digit tip pointing toward
the examiners eye) the curve of the nail forms a tighter curve of
convexity (Fig. 95). subjective
Comment: No objective standards were identied for this
nding. Another way to describe this nding is to say that the
observed curve has a smaller radius than does the typical nail. The
affected digits should be specied.
Nail Narrow
Denition: Decreased width of nail (Fig. 96). subjective
Comment: Standards for newborns were identied [Seaborg and
Bodurtha, 1989] but none were identied for older persons.
Therefore, for newborns, this could be objective, but this is rarely
measured. The affected digits should be specied.
Nail Pits
Denition: Small (typically about 1 mm or less in size) depressions
on the dorsal nail surface (Fig. 97). subjective
Comment: The affected digits should be specied.
FIG. 93. Nail, concave, left hand, F4. See also Figure 103.
Note that this image also shows Tapered ngers, left, F23,
and Broad ngertip, left, F4.
FIG. 94. Nail, fused, T1, right foot. See also Figure 9A. This
patient also has a Broad toe, left, T1 and Cutaneous
syndactyly, partial, left, T23.
FIG. 95. Nails, hyperconvex, left, F3,4. See also Figure 102.
FIG. 96. Nail, narrow, T2, left foot. Note that the length of
this nail is normal, so it is coded as narrow, not small.
FIG. 97. Nails, pitted, F2-4, right hand.
124 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Nail, Ridged
Denition: Longitudinal, linear prominences in the nail plate
(Fig. 98). subjective
Comment: There may be only one, or several ridges. The affected
digits should be specied.
Nail, Short
Denition: Decreased length of nail (Fig. 99). subjective
Comment: Use this designation when the length is reduced but
the width is normal. Standards for newborns were identied
[Seaborg and Bodurtha, 1989] but none were identied for older
persons. Therefore, for newborns, this could be objective, but this is
rarely measured. The affected digits should be specied.
Synonym: Brachyonychia
Nail, Small
Denition: A nail that is diminished in length and width (Fig. 100).
subjective
Comment: This is a bundled term but is retained because of its
common usage. This term may be used when the width and length
are reduced, although it may be preferable to code the patient as
having both Short nail and Narrow nail. Standards for newborns
were identied [Seaborg and Bodurtha, 1989] but none were
identied for older persons. Therefore, for newborns, this could
be objective, but this is rarely measured. The affected digits should
be specied.
Replaces: Hypoplastic nails
Synonym: Micronychia
Nail, Split
Denition: A nail plate that has a longitudinal separation and the
two sections of the nail share the same lateral radius of curvature
(Fig. 101). subjective
Comment: This is distinct from Fused nail, where the two parts
of the nail have a separate radius of curvature. The affected digits
should be specied as described in the introductory comments.
Nails, spoon shaped: See Nail, concave
Nail, Thick
Denition: Nail that appears thick when viewed on end (Fig. 102).
subjective
Comment: No objective standard for nail thickness could be
identied although an unsupported claim suggests that nails
are 0.5 mm in females and 0.6 mm in males (http://www.
emedicine.com/orthoped/topic421.htm). There is a build up of
FIG. 98. Nails, ridged, F1, bilateral.
FIG. 99. Nails, short, F1,5, left hand. See also Figures 15 and
60A. Note that this patient also has Bid nail, F5 left hand;
Broad nger, F5, left hand; Short nger, left hand, F1; and
Short metacarpal, F5 (see Fig. 49).
FIG. 100. Nails, small, left foot. See also Figures 12, 28, and
58A.
FIG. 101. Nail, split, T1, left foot. Note that this image also
shows a Broad toe, T1, left foot andCutaneous syndactyly,
partial, T23, left foot.
BIESECKER ET AL. 125
keratin causing the nail plate to lift away from the nail bed. The
thickened nail plate is usually very hard.
Replaces: Onychogryposis; Pachyonychia
Nail, Thin
Denition: Nail that appears thin when viewed on end (Fig. 103).
subjective
Comment: No objective standard for nail thickness could be
identied. An unsupported claim suggests that nails are 0.5 mm in
females and 0.6 mm in males (http://www.emedicine.com/
orthoped/topic421.htm). Thin nails are usually brittle, may easily
fray, or break at the free edge. Thin nails usually grow slowly but this
denition does not require slow growth of the nail. Note that the
term koilonychia is an abnormal shape of the ngernail where the
nail has raised ridges and is thin and concave. Since it include other
characteristics besides thin nails, it should not be used to indicate
this. The affected digits should be specied.
Onychogryposis: See Nails, thick
Pachyonychia: See Nails, thick
ACKNOWLEDGMENTS
This paper was reviewed and edited by the co-Chairs of the
International Dysmorphologic Terminology working group
(Judith Allanson, Leslie G. Biesecker, John Carey, and Raoul
C.M. Hennekam). This review and editing was necessary to increase
the consistency of formatting and content among the six
manuscripts [Carey et al., 2009; Hall et al., 2009; Hennekam
et al., 2009; Hunter et al., 2009; Allanson et al., 2009b] and this
paper. While the authors of the papers are responsible for the
original denitions and drafting of the papers, nal responsibility
for the content of each paper is shared by the authors and the four
co-Chairs. Images were provided by several of the authors, Raoul
C.M. Hennekam, Helen Hughes, and Julia Fekecs. The efforts of
LGB were supported by the Intramural Research Program of the
National Human Genome Research Institute of the National In-
stitutes of Health.
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FIG. 103. Nails, thin, F2,5, right hand. This image also shows
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126 AMERICAN JOURNAL OF MEDICAL GENETICS PART A
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BIESECKER ET AL. 127
    • "Middle: fifth finger clinodactyly (defined as incurving of the fifth finger toward the radius) [7]. Right: Single transverse palmar crease (defined as when the distal and proximal transverse palmar creases merge into a single transverse palmar crease) [7]. Left photo is from Elements of Morphology [8]. "
    [Show abstract] [Hide abstract] ABSTRACT: In 2011 and 2012, the Division of Microbiology and Infectious Diseases at the National Institute of Allergy and Infectious Diseases, National Institutes of Health, held a series of meetings to provide guidance to investigators regarding study design of clinical trials of vaccines and antimicrobial medications that enroll pregnant women. Assessment of congenital anomalies among infants born to women enrolled in these trials was recognized as a challenging issue, and a workgroup with expertise in epidemiology, pediatrics, genetics, dysmorphology, clinical trials, and infectious diseases was formed to address this issue. The workgroup considered 3 approaches for congenital anomalies assessment that have been developed for use in other studies: (1) maternal report combined with medical records review, (2) standardized photographic assessment and physical examination by a health professional who has received specific training in congenital anomalies, and (3) standardized physical examination by a trained dysmorphologist (combined with maternal interview and medical records review). The strengths and limitations of these approaches were discussed with regard to their use in clinical trials. None of the approaches was deemed appropriate for use in all clinical trials. Instead, the workgroup acknowledged that decisions regarding the optimal method of assessment of congenital anomalies will likely vary depending on the clinical trial, its setting, and the agent under study; in some cases, a combination of approaches may be appropriate. The workgroup recognized the need for more research on approaches to the assessment of congenital anomalies to better guide investigators in optimal design of clinical trials that enroll pregnant women. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.
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    • "Participants agreed to use standardized terms to describe clinical findings. It was accepted to begin using the standard terminology proposed by an international group of dysmorphologist and published in six papers by the American Journal of Medical Genetics [Biesecker et al., 2009; Carey et al., 2009; Hall et al., 2008; Hennekam et al., 2008; Hunter et al., 2008; Allanson et al., 2008]. In addition the group will follow the guidelines proposed by papers by Allanson et al. [2009]; Biesecker and Carey [2011]; Carey et al. [2009] [2012]. "
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