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Abstract

An infant with macular dysfunction, cleft lip and palate, and developmental delay was shown to have an inverted duplication of 11p11.3 leads to p14.1 on the basis of meiotic recombination subsequent to an intrachromosomal "shift" in his mother. A half-sister had previously been shown [3] to have the reciprocal recombinant with resultant deletion of 11p11.3 leads to 11p14.1.

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... Pericentric 1. Garver (1976) 2. Palmer (1977) 3. Pan (1977)/ Garver (1978) 4. Pfeiffer (1987) 5. Therkelsen (1973) 6. Pal (1983) 7. Present case 8. Hastings (1990) 9. Martin (1985) 10. Miller (1979) 11. Strobel(1980) 12. Forsythe (1988) 13. Vekemans (1990) 14. Cohen (1983) 15. ...
... Identification of the insertion was difficult in at least eight of the reported cases (Therkelsen et al. 1973;Garver et al. 1976;Sparkes et al. 1979;Allderdice et al. 1983;Wyandt et al. 1980;Strobel et al. 1980;Valcfircel et al. 1983;Vekemans and Morichon-Delvallez 1990). Four of these were originally interpreted as paracentric inversions with unbalanced meiotic products, and only later were re-interpreted as paracentric insertions by either the same authors (Kelly et al, 1979;Wyandt et al. 1980;Allderdice et al. 1980, t983) or different authors (Sparkes et al. 1979;Hoegerman 1979;Valcgtrcel et al. 1983;Callen et al. 1985). ...
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We describe the phenotype of a child having a recombinant chromosome 3 with a duplication 3q13.2----q25 derived from a paternal inv ins(3)(p25.3q25q13.2). A review of 27 reported cases of intrachromosomal insertions has revealed that for a carrier of intrachromosomal insertion the risk of a child with an unbalanced karyotype is 15%. This risk may be higher for particular insertions. The recombinant chromosome can have a duplication or a deletion of different segments depending on whether the insertion is direct or inverted, paracentric or pericentric, and whether there is meiotic crossing over in the inserted or the interstitial non-inserted segment. Several of the insertions have been difficult to interpret and some of them have been mistaken for paracentric inversions. Caution is therefore indicated in interpreting parental karyotypes of a child with a deletion or a duplication, particularly if it is interstitial. This is because, whereas a risk of recurrence of a child with an unbalanced karyotype is low in de novo cases and for carriers of paracentric inversions, it is high for carriers of insertions.
... Also there are 4 cases with dup [11](p11.3p11.3) with variant clinical features, like macular dysfunction, cleft lip and palate and developmental delay [18], mentally retardation but no other remarkable dysmorphic characteristics [19,20], or features invoking Silver-Russell syndrome [21]. ...
... Reference Karyotype Reason for ascertainment Therkelsen et al. (1973) Palmer et al. (1977) Pan et al. (1977) Mil!er et al. (1979) Strobel et al. (1980) Wyandt et al. (1980) Grass et al. (1981) Allderdice et al. (1983) Cohen et al. (1983) Pal et al. (1983) Martin et al. (1985) dir ins(2)(q34p! 3p24) mv ins(l )(p22q41q25) ins(l )(p32q25q31) ms(7)(pl 5p21q22) mv ins(11)(q14.5p14. ...
... With regard to their karyotypes, breaking points on chromosome llp were found at pll, p12, p13, pl4 and p15 bands in each patient. The duplication of llp15 band, however, was common to all of the patients except for the two cases described by Sanchez et al. (1974) andStrobel et al. (1980). Since the features of 13 patients with llp15 trisomy differ from those of the two patients without l lp15, the 13 patients are included in one group and the rest in a second group. ...
Article
A female infant with partial trisomy 11p(p13pter) resulting from a paternally inherited balanced translocation is described and compared with 14 previously reported cases of trisomy 11p. The patient had macroglossia, umbilical and inguinal hernias, hypotonia, soft and wrinkled skin, dysmorphic face, high-arched palate, hepatosplenomegaly, intestinal malrotation, Meckel's diverticulum, and mental retardation. The patient's karyotype was 46,XX,–4,+der(4), t(4;11)(q35;p13)pat. Of all 15 patients including our case, the clinical features of 13 patients with duplication of the 11p15 band resembled those of Beckwith-Wiedemann syndrome.
Article
We describe a family in whom the phenotypically normal father carries a balanced insertional translocation, ins(14;11)(q23;p12p14). This individual fathered three mentally retarded children, two with a del(11)(p13) and one with a dup(11)(p13). Two other cases of a de novo del(11)(p13) are also described. All four del(11)(p13) cases presented with WAGR, a complex syndrome associated with a predisposition to Wilms' tumor (WT), aniridia (A), genitourinary abnormalities (G), and mental retardation (R). Using an approach combining karyotype analysis, determination of the gene copy number, and RFLP studies employing five 11p13 DNA markers, we were able to define the chromosomal rearrangement involved in each case. Analysis of these WAGR deletions provides further subdivision of band p13 on chromosome 11.
Article
In this report we describe the cytogenetic finding of an intrachromosomal 11p12 duplication in a mildly to moderately mentally retarded 53-year-old man without dysmorphic symptoms.
Article
We report on a girl with a duplication of chromosome band 11p12-->13, which includes the Wilms tumor gene (WT1) and the aniridia gene (PAX6). The girl had borderline developmental delay, mild facial anomalies, and eye abnormalities. Eye findings were also present in most of the 11 other published cases with partial trisomy 11p, including 11p12-->13. Recently, it was shown that introduction of additional copies of the PAX6 gene into mice caused very variable eye abnormalities. Therefore, a PAX6 gene dosage effect is likely to be present in mice and humans. The central nervous system may be less sensitive to an altered PAX6 gene dosage, which is consistent with the borderline developmental delay in the present patient. Urogenital abnormalities were absent in this patient and in most of the other patients with partial trisomy of 11p. Therefore, the effect of a WT1 gene duplication on the embryological development of the urogenital tract remains uncertain.
Article
We present a three generation family in which a father and son have a balanced chromosome translocation between the short arms of chromosomes 5 and 11 (karyotype 46,XY,t(5;11)(p15.3;p15.3)). Two family members have inherited the unbalanced products of this translocation and are trisomic for chromosome 11p15.3-->pter and monosomic for chromosome 5p15.3-->pter (karyotype 46,XY,der(5)t(5;11)(p15.3;p15.3)pat). Paternally derived duplications of 11p15.5 are associated with Beckwith-Wiedemann syndrome (BWS) and both family members trisomic for 11p15.5 had prenatal overgrowth (birth weights >97th centile), macroglossia, coarse facial features, and broad hands. We review the clinical features of BWS patients who have a paternally derived duplication of 11p15.5 and provide evidence for a distinct pattern of dysmorphic features in those with this chromosome duplication. Interestingly, our family is the fifth unrelated family to be reported with a balanced reciprocal translocation between the short arms of chromosomes 5 and 11. The apparently non-random nature of this particular chromosome translocation is suggestive of sequence homology between the two chromosome regions involved in the translocation.
Article
Aniridia in man and Small eye in mice are semidominant developmental disorders caused by mutations within the paired box gene PAX6. Whereas heterozygotes suffer from iris hypoplasia, homozygous mice lack eyes and nasal cavities and exhibit brain abnormalities. To investigate the role of gene dosage in more detail, we have generated yeast artificial chromosome transgenic mice carrying the human PAX6 locus. When crossed onto the Small eye background, the transgene rescues the mutant phenotype. Strikingly, mice carrying multiple copies on a wild-type background show specific developmental abnormalities of the eye, but not of other tissues expressing the gene. Thus, at least five different eye phenotypes are associated with changes in PAX6 expression. We provide evidence that not only reduced, but also increased levels of transcriptional regulators can cause developmental defects.
Article
Multiple 'WT' genes exist. The WT1 gene at chromosomal band 11p13 has been cloned and is known to be important in the etiology of at least some tumors by virtue of the identification of both germline and somatic mutations in WT patients. Genes at 11p15 and 16q are also involved, either as initiating or tumor progression events. An unlocalized familial predisposition gene is also known to be important etiologically. The identification of several genes that are involved in the etiology or progression of WT, the preferential loss of maternally derived alleles in tumor tissue, and the observed reduction to 11p homozygosity in normal tissue DNA from some patients, all strikingly indicate that a simple, one-locus-'two-hit' genetic model for WT is inadequate. The question is not if this model needs to be modified, but how it should be modified, or if it is even valid enough to be a starting point for understanding the genetics of Wilms tumor. To begin to address this, several questions can be asked. Do all Wilms tumors carry mutations at the WT1 locus? Do both alleles at the WT1 locus need to be inactivated or lost for tumorigenesis? Or, instead, do some WT1 mutations act dominantly? Do patients with bilateral disease carry germline mutations as originally hypothesized, or, as more recently suggested, is bilateral disease the result of early somatic mutations, genomic imprinting, or multifactorial inheritance? Must mutations at an 11p15 locus and/or 11p15 LOH accompany WT1 mutations, or do 11p13 and 11p15 mutations act independently of each other? Have tumors from familial WT cases (who do not carry germline WT1 mutations) sustained somatic mutations at the WT1 locus, the 11p15 locus or the 16q locus? Conversely, do tumors from sporadic WT patients carry somatic mutations at the non-11p familial predisposition gene? Will most tumors be found to carry mutations at the same one or two loci, but differ only with regard to whether the mutations are somatic or germline? Are effects of genomic imprinting layered over, so to speak, a framework of classically mendelian mutations, or in some cases is imprinting the mechanism by which genes are inactivated or their normal function modulated? Although not definitive, there are data that bear on some of these questions. Germline mutations have been observed in patients with bilateral tumors, but may not prove to be a universal feature of bilateral disease.(ABSTRACT TRUNCATED AT 400 WORDS)
Article
The localization of protooncogenes on human chromosomes may coincide with chromosome breakpoints of consistent translocations in leukaemias or lymphomas, suggesting a direct involvement of oncogenes in carcinogenesis. For example, in Burkitt's lymphoma consistent translocations may be associated with rearrangements of c-myc. Our assignment of the c-Harvey-ras1 oncogene to chromosome 11, precisely to region 11p11 leads to p15 (ref. 5; not 11p13 as stated in ref. 6), has raised the possibility that this oncogene might have a role in the predisposition to nephroblastoma (Wilms' tumour, WT) seen in the aniridia-WT association (AWTA) that is frequently caused by an interstitial deletion of band 11p (ref. 8). We have now studied the organization and copy number of sequences at three loci mapped to 11p: c-Ha-ras1, insulin and gamma-globin in cells from four individuals with structural rearrangements of the short arm of chromosome 11. Our results reported here rule out a close physical linkage between c-Ha-ras1 and the genes responsible for AWTA, and suggest a more distal localization of the beta-globin cluster than currently assumed.
Article
Two patients with Wilms tumor, iris dysplasia (complete aniridia in one and subtle iris defects in the other), normal karyotypes, and no gene loss demonstrable by enzyme marker and direct DNA analyses are presented. The findings indicate that aniridia and less severe iris defects define a risk for Wilms tumor even in the absence of del (11p13), and that there is as yet no consistent biochemical genetic marker for the aniridia-Wilms tumor association.
Article
The gene for red blood cell (RBC) catalase has recently been mapped to 11p13, and a gene dosage effect has been demonstrated for individuals with triplication or deletion of that region. Deletion of the 11p13 band has also been associated with aniridia, with and without Wilm's tumor. We studied the RBC catalase levels in individuals without detectable chromosomal abnormalities but with aniridia, Wilm's tumor, and the combination of aniridia and Wilms' tumor, to determine whether catalase levels might provide evidence for a submicroscopic chromosomal deletion in the 11p13 region. All karyotypically normal patients were found to have normal catalase levels.
Article
Duplication of chromosome sub-bands 5p14.3 and 5p15.1 in a child resulted in mild mental retardation, apparently without other abnormalities. The duplicated region arises from recombination within a directly inserted segment following a shift within the short arm of the maternal chromosome 5 homologs.
Article
Wilms' tumour probably arises from embryonal kidney cells and occurs in both hereditary and sporadic forms. Knudson and Strong have suggested that both forms of the disease are initiated by two mutational events. In the case of the inherited form, cytogenetic evidence indicates that a germline deletion of chromosome band 11p13 may correspond to one of the two mutations. DNA mapping evidence is consistent with the notion that the tumour susceptibility gene (Wg) on chromosome 11 is actually recessive. Comings has proposed that the dominantly inherited tumours may arise by the inactivation or loss of a diploid pair of regulatory genes which normally suppress the expression of a structural transforming gene (Tg). It has recently been suggested that the N-myc oncogene may serve as a transforming gene in retinoblastoma, although no such gene has yet been identified in Wilms' tumour. We now report that in four cases of Wilms' tumour, insulin-like growth factor-II (IGF-II) transcripts are highly elevated compared with the adjacent normal kidney. In addition, we have mapped the gene for IGF-II to chromosome band 11p14.1, which is in the immediate vicinity of Wg. These findings suggest that IGF-II may be involved in the aetiology of Wilms' tumour.
Article
One-half of all cases of Wilms tumor (WT), a childhood kidney tumor, show loss of heterozygosity at chromosomal band 11p13 loci, suggesting that mutation of one allele and subsequent mutation or loss of the homologous allele are important events in the development of these tumors. The previously reported nonrandom loss of maternal alleles in these tumors implied that the primary mutation occurred on the paternally derived chromosome and that it was "unmasked" by loss of the normal maternal allele. This, in turn, suggests that the paternally derived allele is more mutable than the maternal one. To investigate whether germinal mutations are seen with equal frequency in maternally versus paternally inherited chromosomes, we determined the parental origin of the de novo germinal 11p13 deletions in eight children by typing lymphocyte DNA from these children and from their parents for 11p13 RFLPs. In seven of the eight cases, the de novo deletion was of paternal origin. The one case of maternal origin was unremarkable in terms of the size or extent of the 11p13 deletion, and the child did develop WT. Transmission of 11p13 deletions by both maternal and paternal carriers of balanced translocations has been reported, although maternal inheritance predominates. These data, in addition to the general preponderance of paternally derived, de novo mutations at other loci, suggest that the increased frequency of paternal deletions we observed is due to an increased germinal mutation rate in males.
Article
Full-text available
Deletion of chromosome 11p13 in humans produces the WAGR syndrome, consisting of aniridia (an absence or malformation of the iris), Wilms tumor (nephroblastoma), genitourinary malformations, and mental retardation. An interspecies backcross between Mus musculus/domesticus and Mus spretus was made in order to map the homologous chromosomal region in the mouse genome and to define an animal model of this syndrome. Nine evolutionarily conserved DNA clones from proximal human 11p were localized on mouse chromosome 2 near Small-eyes (Sey), a semidominant mutation that is phenotypically similar to aniridia. Analysis of Dickie's Small-eye (SeyDey), a poorly viable allele that has pleiotropic effects, revealed the deletion of three clones, f3, f8, and k13, which encompass the aniridia (AN2) and Wilms tumor susceptibility genes in man. Unlike their human counterparts, SeyDey/+ mice do not develop nephroblastomas. These findings suggest that the Small-eye defect is genetically equivalent to human aniridia, but that loss of the murine homolog of the Wilms tumor gene is not sufficient for tumor initiation. A comparison among Sey alleles suggests that the AN2 gene product is required for induction of the lens and nasal placodes.
Chapter
Nephroblastoma, or Wilms tumor (WT), is a childhood tumor of the kidney that was described and characterized in several case reports and reviews during the 19th century. It acquired its commonly used eponym after Max Wilms published a monograph on the subject in 1899. Occurring with a frequency of roughly 1 in 10,000 live births (Matsunaga, 1981; Breslow et al., 1983), WT is one of the most common solid tumors of children. Fortunately, it is also one of the most successfully treated childhood cancers; with a triple modality therapy of surgery, chemotherapy, and radiotherapy, the overall 2-yr, disease-free survival rate is now 85% (D’Angio et al., 1989).
Article
A rare chromosomal aberration consisting of a chromosomal shift was found in a woman who had prenatal diagnosis because she had previously had a malformed girl with phenotypic features compatible with the diagnosis of Patau syndrome. Chromosome analysis using G, C, and NOR banding showed a direct intrachromosomal insertion of bands 13q12 to 13q14 onto the short arm of chromosome 13 at band 13p13. We discuss this observation and compare it with other published reports of chromosomal shifts.
Article
The inactivation of two alleles at a locus on the short arm of chromosome 11 (band 11p13) has been suggested to be critical steps in the development of Wilms tumor (WT), a childhood kidney tumor. Two similar candidate WT cDNA clones (WT33 and LK15) have recently been identified on the basis of both their expression in fetal kidney and their location within the smallest region of overlap of somatic 11p13 deletions in some tumors. These homozygous deletions, however, are large and potentially affect more than one gene. Using a cDNA probe to the candidate gene, we have analyzed DNA from both normal and tumor tissue from WT patients, in an effort to detect rearrangements at this locus. We report here a patient with bilateral WT who is heterozygous for a small (less than 11 kb) germinal deletion within this candidate gene. DNA from both tumors is homozygous for this intragenic deletion allele, which, by RNA-PRC sequence analysis, is predicted to encode a protein truncated by 180 amino acids. These data support the identification of this locus as an 11p13 WT gene (WT1) and provide direct molecular data supporting the two-hit mutational model for WT.
Article
We describe a boy with an interstitial deletion of 6(q13–q15) and include “coarse” facial features, upslanting palpebral fissures, thin vermilion border of the upper lip, elongated philtrum, developmental delay, and profound hypotonia. The child's eye findings, pedigree, paucity of maternal ocular changes, and lack of melanin macroglobules in the skin suggest that this individual's phenotype is clinically similar to that of autosomal recessive ocular albinism. Though it is possible that this deletion and his ophthalmic disorder are coincidental, we postulate that the ocular albinism may be due to hemizygosity for a paternally derived ocular albinism gene located on chromosome 6 in the region q13–q15. This patient's deletion is secondary to a recombination of a maternal intrachromosomal inverted insertion of this region. Of the 7 reported 6q1 deletions, this is the only case that is due to a familial chromosome rearrangement.
Article
A direct intrachromosome insertion of chromosome 7 is described, and previous reports of intrachromosomal insertions are listed. All others were ascertained through a phenotypically abnormal proband. Ours is the first presenting with multiple pregnancy losses. Since the risk of chromosomally abnormal liveborns is appreciable, prenatal diagnosis should be made available to known carriers of chromosome insertions.
Article
Pax6 is a highly conserved transcription factor that controls the morphogenesis of various organs. Changes in Pax6 dosage have been shown to affect the formation of multiple tissues. PAX6 haploinsufficiency leads to aniridia, a pan-ocular disease primarily characterized by iris hypoplasia. Herein, we employ a modular system that includes null and overexpressed conditional alleles of Pax6. The use of the Tyrp2-Cre line, active in iris and ciliary body (CB) primordium, enabled us to investigate the effect of varying dosages of Pax6 on the development of these ocular sub-organs. Our findings show that a lack of Pax6 in these regions leads to dysgenesis of the iris and CB, while heterozygosity impedes growth of the iris and maturation of the iris sphincter. Overexpression of the canonical, but not the alternative splice variant of Pax6 results in severe structural aberrations of the CB and hyperplasia of the iris sphincter. A splice variant-specific rescue experiment revealed that both splice variants are able to correct iris hypoplasia, while only the canonical form rescues the sphincter. Overall, these findings demonstrate the dosage-sensitive roles of Pax6 in the formation of both the CB and the iris.
Article
More than 100 cases of deletions that span 11p13-11p14 resulting in WAGR syndrome have been reported in the literature. In contrast, reports of duplications spanning this region are extremely rare. We here report on a deletion of 11p13-11p14 identified in a neonate with severe congenital anomalies including genitourinary abnormalities and aniridia, and the reciprocal duplication identified in his healthy older sibling. Both were derived from a paternal balanced insertion of the 11p region into 18q. The deletion and duplication were characterized by G-banding, FISH and array CGH, and are estimated to include approximately 5.5-5.8 Mb. This single family report highlights the mild phenotypes that can be associated with duplications of chromosomal regions, even those that are larger than 5 Mb and harbor known disease-related genes, and highlights the impact of identifying balanced carrier status in a parent for accurate genetic counseling.
Chapter
Deoxyribonucleic acid (DNA) is the fundamental unit that directs the orchestration of cellular function and transmits traits from one generation to the next. It is a self-reproducing macromolecule that determines the composition of proteins within the cell. The gene is a sequence of DNA that encodes for a single, specific protein or regulates the expression of a gene; just as the DNA is arranged as beads on a necklace, the genes (specific segments of DNA) are similarly aligned. The information contained in the DNA is transcribed to ribonucleic acid (RNA), an intermediary template, which is, in turn, translated to the specific protein. The DNA of functional genes is arranged in exons and introns; exonic sequences are transcribed into RNA, and the intronic sequences are removed. Sequence variation is considerably greater for the introns. The nuclear genes and other untranslated DNA are organized as chromosomes, discrete organelles within the nucleus. The majority of the DNA of a cell is arranged as chromosomes within the nucleus; a small percentage of DNA is within the mitochondria in the cytoplasm of the cell and primarily orchestrates oxidative metabolism. Different species of animals and plants have different numbers of chromosomes; for example, a mouse has 40 and a tomato 24. Humans have 23 pairs, of which 2, an X and a Y, determine gender. Each nucleated cell of the organism has the same DNA as every other cell unless a mutation or chromosomal anomaly has occurred after conception.
Article
The codominant expression of three HLA haplotypes was found in a healthy 21-year-old Black male, whose prometaphase karyotype was normal by light microscopy. He was the sibling of an antenatally diagnosed female fetus with a partial duplication of 6p. The duplication arose from a complex presumably balanced maternal chromosome rearrangement: 46, XX, dir ins(14;6)(14pter→14p11::6p22→6p21.1::14p11→14qter;6pter→6p22::6p21.1→6qter). Chromosomal in situ hybridization using a tritium-labeled genomic clone corresponding to a class I HLA gene revealed two sites of hybridization: at 6p21.3, the band to which this probe has been assigned in normal individuals (Morton et al. 1984a) and a second site at 6p11. We postulate that a recombinational event during meiotic pairing in the mother led to the reintroduction into the normal chromosome 6 homolog of a small segment of the original insertion in chromosme 14 which contained the HLA-A and -B determinants.
Article
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Patients with Silver-Russell syndrome (SRS) show an intrauterine and postnatal growth restriction associated with a variable spectrum of additional features. Genetic or epigenetic alterations on chromosomes 7 and 11 can be detected in several SRS patients; however, a large fraction of cases remains with unknown genetic etiology. Here, we describe the clinical and molecular findings of a patient with a phenotype invoking SRS showing intrauterine and postnatal growth retardation, psychomotor retardation, relative macrocephaly, slightly triangular face with pointed chin, clinodactyly, and a slight body asymmetry, in whom single-nucleotide polymorphism oligonucleotide array analysis led to the identification of a de novo 11p13 duplication containing many genes that could be functionally related with the observed clinical features. Many deletions of chromosome 11p13, resulting in WAGR (Wilms tumor, aniridia, genital anomalies, mental retardation) syndrome, have been described, while only few duplications spanning the same region have been reported so far. To our knowledge, this is the first reported case presenting a SRS carrier of an 11p13 duplication. We propose candidate genes for the observed traits, and in particular, we discuss the possible role of the involvement of 2 noncoding RNAs in the etiology of the phenotype.
Article
Full-text available
Heterozygous mutations of the homeobox genes ALX4 and MSX2 cause skull defects termed enlarged parietal foramina (PFM) and cranium bifidum (CB); a single MSX2 mutation has been documented in a unique craniosynostosis (CRS) family. However, the relative mutational contribution of these genes to PFM/CB and CRS is not known and information on genotype-phenotype correlations is incomplete. We analysed ALX4 and MSX2 in 11 new unrelated cases or families with PFM/CB, 181 cases of CRS, and a single family segregating a submicroscopic deletion of 11p11.2, including ALX4. We explored the correlations between skull defect size and age, gene, and mutation type, and reviewed additional phenotypic manifestations. Four PFM cases had mutations in either ALX4 or MSX2; including previous families, we have identified six ALX4 and six MSX2 mutations, accounting for 11/13 familial, but only 1/6 sporadic cases. The deletion family confirms the delineation of a mental retardation locus to within 1.1 Mb region of 11p11.2. Overall, no significant size difference was found between ALX4- and MSX2-related skull defects, but the ALX4 mutation p.R218Q tends to result in persistent CB and is associated with anatomical abnormalities of the posterior fossa. We conclude that PFM caused by mutations in ALX4 and MSX2 have a similar prevalence and are usually clinically indistinguishable. Mutation screening has a high pickup rate in PFM, especially in familial cases, but is not indicated in CRS.
Article
The role of del (11)(p13) as a cause of aniridia, with and without Wilms tumor, is strengthened by demonstration of this chromosome aberration in 3 patients: monozygous twin girls, both of whom have aniridia and mental retardation and one of whom has a Wilms tumor; and an unrelated boy with aniridia and ambiguous genitalia. The break points defining the interstitial deletion for the twins are 11p13 and 11p15.1, while for the boy they are 11p1302 and 11p14.1. These patients and their karyotypes substantiate the critical importance of chromosome band 11p13 (or its hemizygous representation) in the development of aniridia and an associated Wilms tumor diathesis, as had been suggested previously (Riccardi VM, Sujansky E, Smith AC, Francke U, (1978): Pediatrics 61, 604-610).
Article
We have constructed ideograms of human prometaphase chromosomes from synchronized and from standard 72-h lymphocyte cultures. G banding was achieved by a trypsin-Giemsa (or Wright's stain) method. In addition to light (white) and dark (black) bands, we have distinguished three different shades of grey. This distinction is essential for proper identification of the increasing number of bands displayed by high-resolution chromosomes. The relative amount of chromatin in each category of staining intensity has been calculated and expressed as ‘light value.’ The ideograms represent the maximal number of bands discernible with some consistency on prometaphase chromosomes, i.e., 721 euchromatic and 62 ‘variable’ heterochromatic or heteromorphic bands. The ideograms are based on measurements. On selected printed copies of each chromosome derived from different cells and different individuals, the relative width of each band was measured in relation to the length of the respective chromosome arm. The measurements per chromosome were averaged and used for construction of the ideograms. The distance of each border between bands or sub-bands from the centromere has been calculated on a relative scale, with positions 0 at the centromere and 1.0 at the p terminus or q terminus. The numbering system for bands and sub-bands follows the Paris Conference (1971) recommendations.
Article
A complex structural rearrangement of chromosomes 11, 12 and 13 was found in a normal female who gave birth to an affected child with partial trisomy for the short arm of chromosome 11 and a balanced translocation 12/13. The detailed analysis of the G-banded chromosomes from early metaphases permitted the delineation of new chromosomal bands which in turn proved essential to the identification of this unusual phenomenon.Bei einer normalen Frau, die ein Kind mit partieller Trisomie des kurzen Armes des Chromosoms 11 und eine balancierte Translokation 12/13 hatte, wurde ein kompliziertes strukturelles Rearrangement der Chromosomen 11, 12 und 13 gefunden. Eine detaillierte Analyse der Chromosomen nach Darstellung der G-Banden aus frhen Metaphasen erlaubte die Abgrenzung neuer Chromosomenbanden, die sich ihrerseits als notwendig fr die Analyse dieses seltenen Phnomens erwiesen.
Article
The triad of aniridia, ambiguous genitalia, and mental retardation (AGR triad) is the characteristic clinical feature of three unrelated patients with previously unreported chromosome 11 short arm interstitial deletions. A Wilms' tumor in one patient establishes one cause for the aniridia-Wilms' tumor association. The genetic heterogeneity of aniridia, the AGR triad, and Wilms' tumor are demonstrated, and Wilms' tumor is indicated to be a neoplastic birth defect which can result from a variety of embryologic insults, some of which may be chromosomal or heritable.
Article
A 7-year-old boy with aniridia, Wilms' tumor, and mental retardation, previously reported as having an interstitial deletion of the short arm of chromosome 8 resulting from a t(8p+;11q-) translocation (Ladda et al., 1974), has been restudied using high-resolution trypsin-Giemsa banding of prometaphase chromsomes. The results revealed a complex rearrangement with four break points in 8p, 11p, and 11q, leading to a net loss of an interstitial segment of 11p (region p1407 yields p1304) but not of 8p. His red blood cells contained normal activities of glutathione reductase (gene on 8p) and lactate dehydrogeanse A (gene on 11p12), indicating a gene dosage consistent with the chromosomal findings. The revised interpretation of this case agrees with seven others reported as having aniridia and interstitial 11p deletions in establishing the distal half of band 11p13 as the site of gene(s) which lead to aniridia and predispose to Wilms' tumor if present in a hemizygous state. Possible relationships between heterozygous deletion of specific chromosomal bands 11p13 and 13q14 and the autosomal dominant disorders aniridia, Wilms' tumor, and retinoblastoma, respectively, are discussed.
Article
A child with aniridia, multiple anomalies, severe failure to thrive, and severe psychomotor retardation is shown to have a syndrome similar to, though more severe than, other patients with overlapping deletions of the short arm of chromosome 11 (Pediatrics 64:604, 1978). Her deletion (46,XX,del [11p] [pter yields p14::p11.3 yields qter]) was derived from her mother, who has a chromosome 11 shift (46,XX,der [11] [pter yields p14::p11.3 yields q22::p14 yields p11.3::q22 yields qter]). The significance of del (11p) in the aniridia-Wilms' tumor association is discussed, and the del (11p) basis for aniridia is compared with other genetic bases for aniridia.
Article
A paracentric inversion in chromosome 13, inv(13)(q12q22), is described in a boy with mild mental retardation and multiple minor anomalies. Bromodeoxyuridine-late replication studies showed no changes in the replication pattern of bands in the abnormal chromosome 13. The relation between the proband's phenotype and his inv(13) is unclear.
Article
We report an uncle and niece with duplication and deletion, respectively, of segment 7p15 leads to 7p21 originating from a balanced, intrachromosomal insertion in their mothers. The proposita had prenatal and postnatal growth deficiency, retarded psychomotor development, microcephaly, wide cranial sutures, ocular hypertelorism, small palpebral fissures, apparently low-set and malformed ears, cleft palate, congenital heart defect, hypoplasia of the distal phalanx of first fingers, rocker-bottom feet, persistent cloaca, and imperforate anus. She died at three months. Her maternal uncle has duplication of this segment and is alive at 32 years. He has severe mental deficiency, but normal growth; communicating hydrocephalus was diagnosed at three months.
Article
In three generations of the proband's patrilineal relatives, 14 subjects were found to be carriers of a "shift" insertional chromosome No. 1 (46XX or XY, ins(1)(p32q25q31)). The proband and three female relatives, who were mild to moderate mental retardates with minor congenital anomalies, were trisomic for the insertional segment, (1)q25q31. Another subject, who was a markedly immature female abortus with congenital abnormalities, was found to be monosomic for this same chromosomal segment. The cytogenetic evidence suggests that each of these unbalanced recombinant progeny was the result of a single crossing over in the noninsertional loop of a paternal pachytene bivalent of the balanced insertional chromosome No. 1.
Article
Two sibs, both monosomic for the same portion of 1q (q25q32), had similar severe mental and physical retardation. An older sib was found to be trisomic for the same portion of 1q and less severely affected. These partially monosomic and partially trisomic No. 1 chromosomes resulted from meiotic crossover in the mother, who is a balanced heterozygote of the type 46,XX, ins (1) (p32q25q32).
Article
Clinical findings of partial trisomy 11p are described in a patient bearing t(3;11;20) (p13;p11;q13). The translocation was present in balanced form in her mother (46, XX)t(3;11;20) (p13;p11;q13).
Article
Found partial trisomy of the short arms of chromosome 11 in a profoundly retarded child with multiple physical defects by means of fluorescent karyotyping of the chromosomally-balanced carrier father. Despite 4 pregnancies, the parents failed to produce any living normal children, suggesting selection for the unbalanced chromosomal complement. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Abnormalities of chromosomes 11 and 20
  • Francke
Francke U: Abnormalities of chromosomes 11 and 20. In Yunis JJ (ed): " New Chromosomal
De novo paracentric inversion in a boy with cleft palate and 31:219-225, 1976. Syndromes
  • Riccardi Vm Holmquist
Riccardi VM, Holmquist GP: De novo paracentric inversion in a boy with cleft palate and 31:219-225, 1976. Syndromes. " New York: Academic Press, 1977, pp 245-249. mental retardation. Hum Genet 52:211-215, 1979.
Aniridia caused by a heritable chromosome 11 deletion
  • Hm Hittner
  • Vm Riccardi
  • U Francke
Hittner HM, Riccardi VM, Francke U: Aniridia caused by a heritable chromosome 11 deletion. Ophthalmology 86 : 11 73-11 83, 1979.
pp 245-249. mental retardation
  • Syndromes
Syndromes. " New York: Academic Press, 1977, pp 245-249. mental retardation. Hum Genet 52:211-215, 1979.