Altered CSF levels of monoamines in hereditary spastic paraparesis 10: A case series

Abstract

Objective:
To perform a comprehensive clinical characterization and biochemical CSF profile analyses in 2 Swedish families with hereditary spastic paraparesis (HSP) 10 (SPG10) caused by 2 different mutations in the neuronal kinesin heavy chain gene (KIF5A).

Methods:
Structured clinical assessment, genetic studies, and neuroradiologic and electrophysiological evaluations were performed in 4 patients from 2 families with SPG10. Additional CSF analysis was conducted in 3 patients with regard to levels of neurodegenerative markers and monoamine metabolism.

Results:
All patients exhibited a complex form of HSP with a mild to moderate concurrent axonal polyneuropathy. The heterozygous missense mutations c.767A>G and c.967C>T in KIF5A were found. Wide intrafamilial phenotype variability was evident in both families. CSF analysis demonstrated a mild elevation of neurofilament light (NFL) chain in the patient with longest disease duration. Unexpectedly, all patients exhibited increased levels of the dopamine metabolite, homovanillic acid, whereas decreased levels of the noradrenergic metabolite, 3-methoxy-4-hydroxyphenylglycol, were found in 2 of 3 patients.

Conclusions:
We report on CSF abnormalities in SPG10, demonstrating that NFL elevation is not a mandatory finding but may appear after long-standing disease. Impaired transportation of synaptic proteins may be a possible explanation for the increased dopaminergic turnover and noradrenergic deficiency identified. The reasons for these selective abnormalities, unrelated to obvious clinical features, remain to be explained. Our findings need further confirmation in larger cohorts of patients harboring KIF5A mutations.

Full text

ARTICLE OPEN ACCESS
Altered CSF levels of monoamines in hereditary
spastic paraparesis 10
A case series
Mattias Andr´
easson, MD, Kristina Lagerstedt-Robinson, PhD, Kristin Samuelsson, MD, PhD,
G¨
oran Solders, MD, PhD, Kaj Blennow, MD, PhD, Martin Paucar, MD, PhD,* and Per Svenningsson, MD, PhD*
Neurol Genet 2019;5:e344. doi:10.1212/NXG.0000000000000344
Correspondence
Dr. Andr´
easson
mattias.andreasson@ki.se
Abstract
Objective
To perform a comprehensive clinical characterization and biochemical CSF profile analyses in 2
Swedish families with hereditary spastic paraparesis (HSP) 10 (SPG10) caused by 2 different
mutations in the neuronal kinesin heavy chain gene (KIF5A).
Methods
Structured clinical assessment, genetic studies, and neuroradiologic and electrophysiological
evaluations were performed in 4 patients from 2 families with SPG10. Additional CSF analysis
was conducted in 3 patients with regard to levels of neurodegenerative markers and monoamine
metabolism.
Results
All patients exhibited a complex form of HSP with a mild to moderate concurrent axonal
polyneuropathy. The heterozygous missense mutations c.767A>G and c.967C>T in KIF5A
were found. Wide intrafamilial phenotype variability was evident in both families. CSF analysis
demonstrated a mild elevation of neurofilament light (NFL) chain in the patient with longest
disease duration. Unexpectedly, all patients exhibited increased levels of the dopamine me-
tabolite, homovanillic acid, whereas decreased levels of the noradrenergic metabolite,
3-methoxy-4-hydroxyphenylglycol, were found in 2 of 3 patients.
Conclusions
We report on CSF abnormalities in SPG10, demonstrating that NFL elevation is not a man-
datory finding but may appear after long-standing disease. Impaired transportation of synaptic
proteins may be a possible explanation for the increased dopaminergic turnover and norad-
renergic deficiency identified. The reasons for these selective abnormalities, unrelated to ob-
vious clinical features, remain to be explained. Our findings need further confirmation in larger
cohorts of patients harboring KIF5A mutations.
*Equal contribution.
From the Department of Neurology (M.A., K.S., G.S ., M.P., P.S.), Karolinska University Hosp ital; Center for Neurology (M.A., P.S.), Academic Specialist Center; Department of
Molecular Medicine and Surgery (K.L.-R. ), Karolinska Institutet, and Departmen t of Clinical Genetics, Karolinska Univ ersity Hospital; Department of Clinical Neur ophysiology (G.S.),
Karolinska University Hospital, Stock holm; Department of Clinical Neuroscience ( K.B.), University of Gothenburg; and Departm ent of Clinical Neuroscience (M.A., K.S., G.S., M.P.,
P.S.), Karolinska Institutet, St ockholm, Sweden.
Go to Neurology.org/NG for full disclosures. Funding information is provided at the end of the article.
The Article Processing Charge was funded by the authors.
This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivativesLicense 4.0 (CC BY-NC-ND), which permits downloading
and sharing the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.
Copyright © 2019 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology. 1

Hereditary spastic paraparesis (HSP) comprises a large and
growing group of chronic progressive neurodegenerative
diseases with varying patterns of inheritance, age at onset,
and disease severity. These diseases share a common affec-
tion of the corticospinal tracts. Heterozygous mutations in
the N-terminal motor domain of the neuronal kinesin heavy
chain gene (KIF5A) are associated with autosomal domi-
nant HSP 10 (SPG10) and less commonly with Charcot-
Marie-Tooth type 2, with or without pyramidal signs.
1,2
Rarely, mutations in this gene are also associated with cer-
ebellar ataxia or cognitive impairment.
2
In addition, a recent
genome-wide association study has identified variants in the
C-terminal of KIF5A associated with amyotrophic lateral
sclerosis (ALS).
3
KIF5A encodes one of 2 heavy chain subunits that together
with 2 light chain subunits make up a tetrameric kinesin-1
protein.
1,4,5
This kinesin is crucial for anterograde molecular
axonal transport by binding to microtubule.
4,6
At least 23
mutations in KIF5A with HSP phenotype have been
reported.
1,2,5,7,8
In vitro assays have demonstrated that mutant forms of the
kinesin-1 protein impair the transport of cargo along micro-
tubule.
6
Furthermore, 2 studies on cultured neurons from
Kif5A knockout mice and mice with mutant Kif5A have
demonstrated disturbed axonal bidirectional transport of
mitochondria and neurofilaments, respectively.
9,10
Thus, in
patients, KIF5A mutations are believed responsible for an
axonopathy damaging both the central and peripheral nervous
systems.
1,5,7
Here, we hypothesized that patients with SPG10
would demonstrate an elevation of neurofilament light (NFL)
chain in CSF.
Methods
Standard protocol approvals, registrations,
and patient consents
All patients have given oral and written consent to this
characterization approved by the regional ethical board in
Stockholm, Sweden (2016/2503-31/2).
Clinical assessments
Patients with a known diagnosis of SPG10, followed at Kar-
olinska University Hospital, were eligible for the study. In
total, 4 patients from 2 Swedish families (A and B) with
heterozygous KIF5A mutations were included (figure).
Patients were assessed with standardized clinical examination
that included the Spastic Paraplegia Rating Scale (SPRS),
Friedreich Ataxia Rating Scale part 1: functional staging for
ataxia, Inventory of Non-Ataxia Signs, Instituto de Pesquisa
Clinica Evandro Chagas Scale, Scale for the Assessment and
Rating of Ataxia, and Montreal Cognitive Assessment. The
inclusion of rating scales assessing cerebellar function was
chosen based on reports of ataxia as a feature in patients with
KIF5A mutations and other familial kinesin motor
proteinopathies.
2,11
Standardized examination took place
between January and March of 2018.
Genetic analyses
Both families were examined with targeted genetic analyses
for autosomal dominant HSP (e-Methods, links.lww.com/
NXG/A160).
Biochemical analyses
CSF was collected from 3 patients (III:1 in family A and II:
1, III:1 in family B) by standard procedures. Patient II:1, in
family A, declined lumbar puncture. For patient III:1, in
family A, CSF had been collected in 2012 and since then
stored at −80°C. Levels of the neurodegenerative markers
total tau (t-tau), phosphorylated tau (p-tau), β-amyloid
42/40 (Aβ42/40) ratio, and NFL chain and monoamine
metabolites homovanillic acid (HVA), 5-hydroxyindoleacetic
acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol
(MHPG) were determined (e-Methods, links.lww.com/
NXG/A160).
Figure Pedigrees of the 2 Swedish families with SPG10
Pedigrees of family A and B harboring the c.767A>G (p.Asn256Ser) and
c.967C>T (p.Arg323Trp) mutations in KIF5A, respectively. Patient I:1 in family
A, due to lack of comprehensive medical notes, is considered possibly
symptomatic based on historical description.
Glossary
5-HIAA = 5-hydroxyindoleacetic acid; ALS = amyotrophic lateral sclerosis; HSP = hereditary spastic paraparesis; HVA =
homovanillic acid; KIF5A = neuronal kinesin heavy chain gene; MHPG = 3-methoxy-4-hydroxyphenylglycol; NFL =
neurofilament light; PNP = polyneuropathy; SPRS = Spastic Paraplegia Rating Scale.
2Neurology: Genetics | Volume 5, Number 4 | August 2019 Neurology.org/NG

Electrophysiology
Motor and sensory nerve conduction studies were compiled
from all 4 patients including, at a minimum, unilateral as-
sessment of the median, peroneal, tibial, and sural nerves.
Nerve conduction studies were conducted with Natus, Viking
EDX (Cephalon A/S; Denmark). Quantitative sensory test-
ing, detecting perception thresholds for cold and heat, was
assessed bilaterally in the lateral foot and unilaterally in the
hand with Medusa, TSA II (Cephalon A/S; Denmark).
Neuroimaging
Historic data from brain and spinal cord MRI were compiled
and reviewed.
Data availability statement
Anonymized data will be shared by request from any qualified
investigator.
Results
The previously reported heterozygous mutations in KIF5A,
c.767A>G (p.Asn256Ser) and c.967C>T (p.Arg323Trp)
were found in family A and B, respectively.
1,5
Briefly, all the
affected patients presented with a variable degree of spastic
paraparesis, which is in line with previous descriptions.
1,2,5,7,8
Onset was at adult age in all but one case (III:1 in family B), in
which the onset was insidious during childhood. All patients
had variable degrees of polyneuropathy (PNP). The index
case in family B reported neuropathic symptoms many years
after onset of paraparesis, and electrodiagnostic testing
demonstrated a moderate axonal sensorimotor PNP. The
historical rate of overall clinical progression was slow in both
families. We did not find evidence of cerebellar ataxia, psy-
chiatric symptoms, or cognitive impairment. None of the
patients were treated with psychotropic medications. Neu-
roimaging was normal. A summary of clinical, radiologic, and
electrodiagnostic characteristics for both families is shown in
table 1.
CSF-NFL was elevated only in the patient with the longest
disease duration. In addition, and more unexpected, we
found in all tested patients elevated CSF-HVA levels, and in
2 patients, CSF-MHPG was reduced. The serotonin me-
tabolite (5-HIAA), Aβ42/40 ratio, and t-tau and p-tau levels
were normal. Results from CSF analyses are presented in
table 2. Detailed case descriptions are included in the sup-
plemental data (e-Clinical phenotypes, links.lww.com/
NXG/A161).
Discussion
There is a need for biomarkers and disease-modifying treat-
ments for HSP diseases. The reasons for intrafamilial phe-
notype variability in SPG10 remain to be elucidated.
1,7
This
variation is similar to what is seen in other forms of familial
Table 1 Electrodiagnostic, neuroradiologic, genetic, and clinical features of 2 families with SPG10
Patient
Age at
onset (y)
Presenting
symptoms
Age at study
inclusion (y) Genotype MoCA SPRS Pyramidal signs
FARS
stage
INAS
count IPEC SARA
Brain
MRI
Spine
MRI NCS and QST
A I:1 50–60
a
Impaired gait Died at age 90 ———— ———————
A II:1 33 Impaired gait 67 c.767A>G 28 11 Hyperreflexia, spastic gait,
and Babinski sign
2574—NAD Mild mixed sensorimotor PNP
including small fibers (C and Aδ)
A III:1 34 Impaired gait
and leg cramps
45 c.767A>G 28 19 Hyperreflexia, ankle clonus,
spastic gait, and Babinski sign
3.5 6 14 6 NAD NAD Mild axonal sensory PNP
B II:1 26 Impaired gait
and imbalance
66 c.967C>T 26 26 Pronounced scissor gait and
equivocal Babinski sign
4 4 12 12.5 NAD NAD Moderate axonal sensorimotor
PNP
B III:1 Childhood Impaired gait
and
paresthesia
32 c.967C>T 30 7 Spastic gait, ankle clonus, and
equivocal Babinski sign
2 6 4 3 NAD NAD Moderate axonal sensorimotor
PNP including small fibers (Aδ)
Abbreviations: FARS stage = Friedreich Ataxia Rating Scale part 1, Functional Staging for Ataxia; INAS count = Inventory of Non-Ataxia Signs; IPEC = Instituto de Pesquisa Clinica Evandro Chagas Scale; mixed = axonal and
demyelinating features present; MoCA = Montreal Cognitive Assessment; NAD = nothing abnormal detected; NCS = nerve conduction study; PNP = polyneuropathy; QST = quantitative sensory testing; SARA = Scale for the
Assessment and Rating of Ataxia; SPRS = Spastic Paraplegia Rating Scale.
Results from ancillary testing and clinical examination. All clinical rating scales have been conducted in the spring of 2018.
a
Clinical data based on the historical account provided by the patient’s daughter (e-Clinical phenotypes, links.lww.com/NXG/A161).
Neurology.org/NG Neurology: Genetics | Volume 5, Number 4 | August 2019 3

kinesin motor proteinopathies such as SPG30 (KIF1A) and
SPG58 (KIF1C); however, these diseases are biallelic and
present with a more severe phenotype than SPG10.
11,12
An impairment of axonal transport, with resulting length-
dependent axonal degeneration, forms the main theory of
the underlying pathophysiology in SPG10.
1
CSF levels of
NFL, an important cytoskeletal component of the axon,
were mildly elevated in the patient with longest disease
duration. This patient also demonstrated the highest SPRS
score (table 1). Because mutated KIF5A is known to impair
axonal transport of neurofilaments, at least in vitro, we were
expecting a more general elevation in our patients.
9
How-
ever, NFL elevation was not evident in the 2 younger
patients why such elevation cannot be viewed as an obligate
finding in SPG10. These results are in contrast with studies
in ALS, where NFL has been proposed as a biomarker.
13
Furthermore, elevated CSF levels of phosphorylated neu-
rofilament heavy chain in patients with HSP (n = 9) com-
pared with controls have been reported in a previous
study.
14
It will be interesting to study NFL levels in patients
with ALS harboring KIF5A mutations.
Assuming that intact axonal transport is important to main-
tain synaptic supply of monoamines, we analyzed these
metabolites. Surprisingly, CSF-HVA was elevated in all tested
patients, of which none had a history of mood disturbance,
psychotic behaviors, or treatment with psychotropic drugs.
Thus, the clinical correlates of this abnormality is unclear. In
addition, 2 patients had decreased levels of the noradrenergic
metabolite MHPG in CSF. In keeping with the proposed
pathophysiology of an underlying axonopathy in SPG10,
deficiency of various neurotransmitters such as noradrenaline
may either reflect impaired transportation of synaptic proteins
or an epiphenomenon. Regardless, the specificity of these
abnormalities remains to be explained.
Small sample size is the main limitation of this study. In ad-
dition, we cannot rule out that the prolonged CSF storage
time (III:1 in family A) might have underestimated the values
of t-tau and Aβ42/40 ratio.
Previous reports on the CSF profile in patients with KIF5A
mutations are rare. Thus, future studies in larger cohorts are
needed to better discern whether noradrenergic deficiency
and increased dopaminergic neurotransmission are prevalent
findings in SPG10, other kinesin proteinopathies, and/or
patients with ALS with KIF5A mutations. It will also be im-
portant to delineate potential clinical correlates to these
changes in monoaminergic neurotransmission.
Acknowledgment
The authors are grateful to the patients who participated in
the study. Funding was obtained from the ALF program at the
Stockholm City Council. P. Svenningsson is a Wallenberg
Clinical Scholar. M. Paucar obtained funding from the
Swedish Society for Medical Research.
Study funding
This study was funded by the collaboration agreement be-
tween Karolinska Institutet and Stockholm County Council
(ALF). Per Svenningsson is a Wallenberg Clinical Scholar.
Martin Paucar obtained funding from the Swedish Society for
Medical Research.
Disclosure
M. Andr´easson has received a contribution from NEURO
Sweden (Neurof¨orbundet) for another study. K. Lagerstedt-
Robinson and K. Samuelsson report no disclosures. G. Sol-
ders has received an unconditional grant from Sanofi/
Genzyme for another study. K. Blennow has served as a con-
sultant or at advisory boards for Alector, Alzheon, CogRx,
Biogen, Lilly, Novartis, and Roche Diagnostics and is a co-
founder of Brain Biomarker Solutions in Gothenburg AB,
a GU Venture-based platform company at the University of
Gothenburg, all unrelated to the work presented in this article.
M. Paucar and P. Svenningsson report no disclosures. Go to
Neurology.org/NG for full disclosures.
Table 2 CSF profiles of 3 patients with SPG10
Patient
t-Tau (pg/mL)
[<300 (18–45 years)]
[<400 (>45 years)]
p-Tau (pg/mL)
[<60 (20–60 years)]
[<80 (>60 years)]
Aβ42/40
[>0.89]
NFL (pg/mL)
[<560 (30–39 years)]
[<1850 (>60 years)]
HVA
(nmol/L)
[40–170]
5-HIAA
(nmol/L)
[50–170]
MHPG
(nmol/L)
[65–140]
A I:1 — — —— ———
A II:1 — — —— ———
A III:1 24 26 0.90 517 208
a
141 38
a
B II:1 320 45 1.07 2,285
a
237
a
107 87
B III:1 171 32 1.02 432 272
a
101 60
a
Abbreviations: 5-HIAA = 5-hydroxyindoleacetic acid; HVA = homovanillic acid; MHPG = 3-methoxy-4-hydroxyphenylglycol; NFL = neurofilament light.
Biochemical characteristics of 3 patients with regard to markers of neurodegeneration and monoamine metabolism. A significant elevation of NFL in the
patient in family B with the longest disease duration (II:1) is demonstrated, possibly reflecting axonal damage. Elevated HVA, reflecting increased dopamine
turnover, is seen in all 3 patients. Furthermore, in 2 patients, biochemical signs of decreased noradrenergic turnover are present.
a
Indicates value outside reference range.
4Neurology: Genetics | Volume 5, Number 4 | August 2019 Neurology.org/NG

Publication history
Received by Neurology: Genetics February 6, 2019. Accepted in final form
May 13, 2019.
References
1. Reid E, Kloos M, Ashley-Koch A, et al. A kinesin heavy chain (KIF5A) mutation in
hereditary spastic paraplegia (SPG10). Am J Hum Genet 2002;71:1189–1194.
2. Liu Y, Laur´a M, Hersheson J, et al. Extended phenotypic spectrum of KIF5A muta-
tions: from spastic paraplegia to axonal neuropathy. Neurology 2014;83:612–619.
3. Nicolas A, Kenna KP, Renton AE, et al. Genome-wide analyses identify KIF5A as
a novel ALS gene. Neuron 2018;97:1268–1283.
4. Hirokawa N, Noda Y, Tanaka Y, Niwa S. Kinesin superfamily motor proteins and
intracellular transport. Nat Rev Mol Cell Biol 2009;10:682–696.
5. Rinal di F, Bassi MT, Todeschini A, et al. A novel mutation in motor domain of KIF5A
associated with an HSP/axonal neuropathy phenotype. J Clin Neuromuscul Dis 2015;
16:153–158.
6. Ebbing B, Mann K, Starosta A, et al. Effect of spastic paraplegia mutations in KIF5A
kinesin on transport activity. Hum Mol Genet 2008;17:1245–1252.
7. L ´opez E, Casasnovas C, Gim´enez J, Santamar´ıa R, Terrazas JM, Volpini V. Identifi-
cation of two novel KIF5A mutations in hereditary spastic paraplegia associated with
mild peripheral neuropathy. J Neurol Sci 2015;358:422–427.
8. Collongues N, Depienne C, Boehm N, et al. Novel SPG10 mutation associated with
dysautonomia, spinal cord atrophy, and skin biopsy abnormality. Eur J Neurol 2013;
20:398–401.
9. Wang L, Brown A. A hereditary spastic paraplegia mutation in kinesin-1A/KIF5A
disrupts neurofilament transport. Mol Neurodegener 2010;5:52.
10. Karle KN, M¨ockelD, Reid E, Sch ¨ols L. Axonal transport deficit in a KIF5A(-/-) mouse
model. Neurogenetics 2012;13:169–179.
11. Dor T, Cinnamon Y, Raymond L, et al. KIF1C mu tations in two families with hereditary
spastic parapares and cerebellar dysfunction. J Med Genet 2014;51:137–142.
12. Erlich Y, Edvardson S, Hodges E, et al. Exome sequencing and disease-network
analysis of a single family implicate a mutation in KIF1A in hereditary spastic para-
paresis. Genome Res 2011;21:658–664.
13. Gaiani A, Martinelli I, Bello L, et al. Diagnostic and prognostic biomarkers in
amyotrophic lateral sclerosis: neurofilament light chain levels in definite subtypes of
disease. JAMA Neurol 2007;74:525–532.
14. Zucchi E, Bedin R, Fasano A, et al. Cerebrospinal fluid neurofilaments may discriminate
upper motor neuron syndromes: a pilot study. Neurodegener Dis 2018;18:255–261.
Appendix Authors
Name Location Role Contribution
Mattias
Andr´
easson,
MD
Karolinska
University Hospital,
Karolinska Institutet
and Academic
Specialist Center,
Stockholm
Author Drafting and
revision of the
manuscript; study
concept and design;
and analysis and
interpretation of
data
Kristina
Lagerstedt-
Robinson, PhD
Karolinska
University Hospital
and Karolinska
Institutet,
Stockholm
Author Interpretation of
genetic tests and
revision of the
manuscript
Kristin
Samuelsson,
MD, PhD
Karolinska
University Hospital,
Stockholm
Author Interpretation of
data and revision of
the manuscript
G¨
oran Solders,
MD, PhD
Karolinska
University Hospital,
Stockholm
Author Interpretation of
neurophysiologic
studies and clinical
data and revision of
the manuscript
Kaj Blennow,
MD, PhD
Clinical
Neuroscience,
University of
Gothenburg
Author CSF analyses;
interpretation of
data; and revision of
the manuscript
Martin Paucar,
MD, PhD
Karolinska
University Hospital
and Karolinska
Institute, Stockholm
Author Revision of the
manuscript; study
concept and design;
analysis and
interpretation of
data; and study
supervision and
coordination
Appendix (continued)
Name Location Role Contribution
Per
Svenningsson,
MD, PhD
Karolinska
University Hospital
and Karolinska
Institute, Stockholm
Author Revision of the
manuscript;
analysis and
interpretation of
data; study
supervision and
coordination; and
obtaining funding
Neurology.org/NG Neurology: Genetics | Volume 5, Number 4 | August 2019 5

DOI 10.1212/NXG.0000000000000344
2019;5; Neurol Genet
Mattias Andréasson, Kristina Lagerstedt-Robinson, Kristin Samuelsson, et al.
Altered CSF levels of monoamines in hereditary spastic paraparesis 10: A case series
This information is current as of June 12, 2019
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