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Contractures and hypertrophic cardiomyopathy in a novel FHL1 mutation.

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ANNALS
of Neurology
spastic cerebral
1114 –1124.
palsy.
Neurosci
Biobehav
Rev
2007;31:
18.
Stanfield BB, O’Leary DD. The transient corticospinal projection
from the occipital cortex during postnatal development of the
rat. J Comp Neurol 1985;238:236 –248.
19.
Raju T, Nelson K, Ferriero D, Lynch J. Ischemic perinatal stroke:
summary of a workshop sponsored by the National Institute of
Child Health and Human Development and the National Institute
of Neurological Disorders and Stroke. Pediatrics 2007;120:
609 – 616.
20.
Chandrasekaran A, Shah R, Crair M. Developmental homeostasis of
mouse retinocollicular synapses. J Neurosci 2007;27:1746 –1755.
21.
Ben-Zvi A, Yagil Z, Hagalili Y, et al. Semaphorin 3A and
neurotrophins: a balance between apoptosis and survival signaling
in embryonic DRG neurons. J Neurochem 2006;96:585–597.
22.
Hanz S, Fainzilber M. Integration of retrograde axonal and nuclear transport mechanisms in neurons: implications for therapeutics. Neuroscientist 2004;10:404 – 408.
Contractures and
Hypertrophic Cardiomyopathy
in a Novel FHL1 Mutation
Hans Knoblauch, MD,1 Christian Geier, MD,2
Stephanie Adams, MD,1 Birgit Budde, PhD,3
André Rudolph, MD,4 Ute Zacharias, PhD,1
Jeannette Schulz-Menger, MD,4
Andreas Spuler, MD,5 Rabah Ben Yaou, MD,6
Peter Nürnberg, MD,3 Thomas Voit, MD,6
Gisele Bonne, PhD,6 and Simone Spuler, MD1
We investigated a large German family (n ⫽ 37) with
male members who had contractures, rigid spine syndrome, and hypertrophic cardiomyopathy. Muscle
weakness or atrophy was not prominent in affected
individuals. Muscle biopsy disclosed a myopathic pattern with cytoplasmic bodies. We used microsatellite
markers and found linkage to a locus at Xq26-28, a
region harboring the FHL1 gene. We sequenced FHL1
1
From the Muscle Research Unit, Experimental and Clinical Research
Center, Charité University Medicine Berlin; 2Department of Cardiology, Virchow Klinikum, Charité University Medicine Berlin, Berlin; 3Cologne Center for Genomics, Cologne; 4Department of Cardiology,
HELIOS-Klinikum Berlin; 5Department of Neurosurgery, HELIOSKlinikum Berlin, Berlin, Germany; and 6Institut de Myologie, University
Marie et Pierre Curie, Paris, France.
Address correspondence to Dr Spuler, Muscle Research Unit, Experimental and Clinical Research Center, Charité University Medicine Berlin, Lindenberger Weg 80, 13125 Berlin, Germany. E-mail:
simone.spuler@charite.de
Received May 21, 2009, and in revised form Jul 24. Accepted for
publication Aug 11, 2009.
Published online in Wiley InterScience (www.interscience.wiley.com).
DOI: 10.1002/ana.21839
Additional Supporting Information may be found in the online version
of this article.
136
and identified a new missense mutation within the
third LIM domain that replaces a highly conserved
cysteine by an arginine (c.625T⬎C; p.C209R). Our
finding expands the phenotypic spectrum of the recently identified FHL1-associated myopathies and widens the differential diagnosis of Emery–Dreifuss–like
syndromes.
ANN NEUROL 2010;67:136 –140
L
“
IM domains,” named after their initial discovery in
the proteins Lin11, Isl-1, and Mec-3, are protein
structural domains composed of two contiguous zinc finger domains separated by a two-amino acid residue hydrophobic linker. Recently, mutations in the gene encoding the “four-and-a-half” LIM-domain protein (FHL1)
have been identified resulting in human reducing body
myopathy, scapuloperoneal myopathy, and postural muscular atrophy with generalized muscle hypertrophy.1–3
FHL1 proteins are a small family of LIM-only proteins
that are highly expressed in skeletal muscle and heart.
LIM domains feature cysteine-rich tandem-zinc fingers
that are involved in protein-protein interaction.4 FHL1 is
involved in mechanical sensing within the sarcomere and
also in transcriptional regulation. Three splice variants of
FHL1 (FHL1a, FHL1b, and FHL1c [identical to
KyoT2]) exist, all of which contain the N-terminal twoand-a-half LIM domains; however, LIM domains 3 and 4
are absent in FHL1c. Most known protein-binding partners of FHL1 bind to the second LIM domain, such as
Raf1, MEK2, or ERK2. FHL1 mutations leading to the
severe phenotypes of reducing body myopathy are also localized in the second LIM domain. We describe here a
novel mutation within the third LIM domain of FHL1.
Our finding expands the known clinical phenotypes to
include an Emery–Dreifuss–like syndrome.
Subjects and Methods
Index patients of a large German family presented with contractures of the Achilles tendon and cardiac left ventricular hypertrophy. We examined 35 members of this family. Twenty-eight
underwent cardiac magnetic resonance imaging, all had electrocardiograms done, and 31 were included in the genetic analysis.
Three patients underwent a muscle biopsy. Our internal review
board approved the studies, and written, informed consent was
obtained. Two members of this family were reported earlier but
died before this investigation.5
Results
Clinical Examination, Genetic Studies, and
Muscle Pathology
The pedigree is shown in Figure A. The clinical findings
are summarized in the Table. Nine male patients, 14 to
60 years old, presented with contractures at the ankle or
knee, or both, and rigid spine syndrome, as shown in FigVolume 67, No. 1
Knoblauch et al: HCM and FHL1
FIGURE: (A) Pedigree. Black symbols indicate affected male individuals; gray symbols indicate clinically mildly affected
women; plus signs indicate the presence of the FHL1 c.625T>C mutation; minus signs indicate the absence of the FHL1
c.625T>C mutation; plus signs within parentheses indicate the presence of the FHL1 c.625T>C mutation based on haplotype data. (B) Rigid spine syndrome in Patient VI:8. (C) Cardiac magnetic resonance imaging showing asymmetric left
ventricular hypertrophy and late gadolinium enhancement representing myocardial fibrosis (arrow). (D) Schematic representation of the structure of the FHL1-protein. Demonstrated is the position of the mutated region within the third LIM domain
exchanging a highly conserved cysteine for arginine. (E) Muscle histology (m. vastus lateralis) from affected Patient IV:9
(Engel’s Gomori-trichrome staining) showing pathological variety in fiber diameter, necrotic fibers, internal nuclei, cytoplasmatic bodies, and increased connective tissue. (F, G) Immunostaining of skeletal muscle (m. vastus lateralis) from affected
Patients IV:9 (F) and V:4 (G) using polyclonal rabbit anti-FHL1 (1:150; Abcam, Cambridge, MA) and goat anti–rabbit-Cy3
(Jackson Laboratory, Bar Harbor, ME).
January, 2010
137
ANNALS
of Neurology
TABLE: Clinical Characteristics of Patients Carrying the X-Chromosomal FHL1 p.C209R Mutation
Patient No.
Male Patients
III:5b
Age at
CK
Age at
Examination, yr Onset, yr Level
Rigid Contractures Cardiac
Spine
Findingsa
Comorbidities
3⫻ 1
⫹
⫹
10-20
Normal
⫹
⫹
50
⬍10
1
⫹
⫹
10-20
1
⫹
⫹
V:4
42 (Voit and
colleagues5)
51
⬎20
5⫻ 1
⫹
⫹
V:6b
26
⬍10
Normal
⫹
⫹
VI:5
14
⬍10
2⫻ 1
⫹
⫹
VI:6
21
⬍10
Normal
⫹
⫹
VI:8
Female
Carriers
IV:4
IV:6b
15
⬍10
n.d.
⫹
⫹
Hypertrophic
Deceased at age
cardiomyopathy 27 years
because of
cardiac and
renal failure
Hypertrophic
None
cardiomyopathy
Apical
None
myocardial
thinning
Normal
None
64
Normal
⫺
⫺
Normal
IV:8b
IV:11
V:13
V:14b
52
53
53
34
36
Normal
Normal
Normal
Normal
n.d.
⫺
(⫹)c
⫺
⫺
n.d.
⫺
⫺
⫺
⫺
n.d.
n.d.
Normal
Normal
VI:3
VI:4
18
7
Normal
(1)
⫹
⫺
⫺
⫺
Normal
IV:5
62 (Voit and
colleagues5)
60
IV:9
IV:12b
Hypertrophic
cardiomyopathy
Left ventricular
hypertrophy
atrial
fibrillation,
septal fibrosis
Hypertrophic
cardiomyopathy
Hypertrophic
cardiomyopathy
Left ventricular
hypertrophy,
focal fibrosis
Left ventricular
hypertrophy
Scoliosis
Hypertension
Scoliosis,
funnel chest
Death at age
51
Hypertension
Hypertension
Hypertension;
violent death at
age 38 years
a
Diagnosis is based on cardiac magnetic resonance imaging, echocardiography, and electrocardiogram.
Haplotype consistent with FHL1 p.C209R mutation.
c
Finger-ground distance ⬍15cm when bending forward.
CK ⫽ creatine kinase; n.d. ⫽ not determined.
b
ure B. Ankle and knee contractures became evident between early childhood and the third decade of life. Apart
from one patient who was unable to sit up from the supine position, none of the patients had muscle weakness,
138
muscular atrophy, or scapular winging. Their overall appearance was muscular but not athletic. Creatine kinase
(CK) concentration was normal or slightly increased.
The cardiac examination showed hypertrophic carVolume 67, No. 1
Knoblauch et al: HCM and FHL1
diomyopathy (see Fig, C) in five and left ventricular hypertrophy, cardiac fibrosis, and hypertension in two male
affected patients. Except for Patient IV:5, who had atrial
fibrillation, we found no rhythm conduction abnormalities. Holter monitoring was performed in male mutation
carriers IV:9, V:6, and V:4, and female mutation carrier
V:13. There was no evidence of rhythm abnormalities.
Subject V:6 had died at age 27 years from heart and renal
failure. The other male members of the family (n ⫽ 11)
had no contractures and no rigid spine, although CK concentration increase was found in two and minimal abnormalities unrelated to hypertrophic cardiomyopathy on
cardiac magnetic resonance imaging in four others. The
female family members were more difficult to assign
whether they could be affected. Two women aged 53 and
18 years (Subjects IV:8 and VI:3) had a finger-ground
distance more than 15 cm when bending forward. Other
evidence for contractures or rigid spine was not seen in
female probands. One female individual had left ventricular hypertrophy and hypertension. The CK levels were
normal in all women, and muscle weakness was never
identified. We inspected the family tree and noted that
male-to-male transmission never occurred. For the period
the patients have been investigated by us and according to
the patients’ histories, the disease progressed slowly. None
of the patients was or became wheelchair bound.
The clinical examination suggested an X-linked disease transmission. A genome-wide linkage analysis was
conducted. A logarithm of odds score of 3.07 was yielded
for chromosome Xq26-q28, and FHL1 was identified as a
candidate gene within this interval. FHL1 was analyzed,
and a single base-pair substitution (c.625T⬎C) in exon 6
exchanging a highly conserved cysteine residue by arginine within the third LIM domain of FHL1 was identified (p.C209R) (see Fig, D). Subsequently, all available
family members were screened for the presence or absence
of the mutation. All male individuals classified as being
affected based on phenotypic data were carriers of the
mutation, whereas none of the clinically unaffected male
individuals carried the mutation.
Three muscle biopsy specimens were available: two
from male patients (IV:9 and V:4) and one from a female
carrier of FHL1 p.C209R, who was asymptomatic (V:13).
We consistently found cytoplasmic bodies in all three
specimens; however, reducing bodies were never present
as determined by reaction for menadione-linked ␣glycerophosphate dehydrogenase. Biopsy sample from Patient IV:9 was most severely affected demonstrating
pathological variation in fiber size, high number of fibers
with internalized nuclei, necrotic and regenerating fibers,
split fibers, increase in connective tissue, and multiple cyJanuary, 2010
toplasmic bodies (see Fig, E). The specimen from Patient
V:4 displayed mild myopathic features in addition to
sparse cytoplasmic bodies, and the female carrier had cytoplasmic bodies in two fibers as the only pathological
finding. Immunostaining using an anti-FHL1 antibody
demonstrated FHL1-positive aggregates in a small number of fibers (see Figs, F and G). Western blot analysis
showed a reduced but not absent expression of FHL1 in
muscle tissue of two affected male individuals (IV:9 and
V:4). The level of FHL1 expression in the female mutation carrier V:13 was slightly reduced as compared with
control subjects (see supplementary data).
Discussion
We present a new clinical phenotype associated with a
new mutation in FHL1 in the third LIM domain that has
to date not been recognized as causing a human disease.
The distinguishing clinical features are early onset of contractures and rigid spine associated with hypertrophic cardiomyopathy, in the absence of conduction defects, weakness, or atrophy until old age. Histologically, cytoplasmic
bodies are the common denominator in affected persons.
Other features described in patients with FHL1 mutations
such as increase in CK concentration, muscle atrophy,
athletic habitus, scapular winging, short neck, and gait
problems are absent in the milder phenotype described
here. Furthermore, the mode of transmission is
X-chromosomal recessive in contrast with X-chromosomal
dominant.
The FHL1 c.605T⬎C missense mutation is located
in exon 6, which encodes most of the third LIM domain
of FHL1. Each LIM domain is composed of a tandem
zinc-finger protein interaction motif, each including four
cysteine residues, which enable zinc binding. Within the
second zinc-finger interaction motif of the third LIM domain, the third cysteine residue is exchanged by arginine.
FHL1 is expressed in three different isoforms. FHL1A is
the full-length protein; FHL1B, or SLIMMER, contains
LIM domains 1 to 3 plus nuclear recognition and export
signals; FHL1C (or KyoT2) contains only LIM domains
1 and 2 but no nuclear localization signal. The FHL1
c.605T⬎C is a novel mutation that affects exclusively isoforms FHL1A and FHL1B, but not isoform FHL1C. The
structural integrity of LIM domains also depends on zinc
coordination. Therefore, mutations in one of the zinccoordinating residues abolish zinc binding and destabilize
the entire domain. The FHL1 p.C209R mutation does
affect one of the essential zinc-binding cysteine residues
and likely destabilizes the third LIM domain. The reduced FHL1 concentration demonstrated on Western
blotting is in accordance with this assumption.6 Cur139
ANNALS
of Neurology
rently, it is not known how the p.C209R mutation causes
the hypertrophic cardiomyopathy. Protein binding partners of the third LIM domain of FHL1 have not been
identified up to now. In this context, it may be of interest
that mutations affecting a single cysteine in a different
muscle and heart, specific four-and-a-half-LIM-protein,
MLP, also cause hypertrophic cardiomyopathy with a
mild skeletal muscle phenotype. However, these patients
have no contractures and no prominent histological alterations.7
The phenotype should be classified as an Emery–
Dreifuss–like syndrome and expands the differential diagnosis of this condition. Classic Emery–Dreifuss muscular
dystrophy with early contractures, slowly progressive muscle weakness, and dilatative cardiomyopathy with rhythm
abnormalities is an X-linked disorder caused by mutations
in the nuclear envelope protein emerin (X-EMD). Autosomal dominant Emery-Dreifuss muscular dystrophy differs little from X-EMD clinically and has also been linked
to a nuclear envelope protein, namely, lamin A/C.8 At
first glance, FHL1 has nothing to do with the nuclear
envelope and appears to be an exception from the link
between Emery–Dreifuss syndrome and this anatomical
structure. However, FHL1 shuttles between cytoplasm
and nucleus, and regulates many cellular processes, including differentiation, transcription, and signal transduction through interaction with other proteins. Binding
partners of the third LIM domain of FHL1 are not
known. We speculate on an interaction between the nuclear envelope and the third LIM domain of FHL1, although detailed studies are necessary to test this hypothesis. We are aware that FHL1 physically and functionally
interacts with SMAD proteins,9 which are second messengers of myostatin and which were previously linked to
muscle hypertrophy in persons with lamin A/C mutations.10 We believe that our findings expand the investi-
140
gative spectrum focusing on Emery–Dreifuss syndromes,
LIM mutations, and muscle diseases.
This project was supported by the Deutsche Forschungsgemeinschaft (DFG; KFO 192); grant number SP1152/8-1
to U.Z. and S.S. and LU435/10-1 to H.K. (Gerok fellowship) and S.S.
We thank Dr F. C. Luft for discussion of the manuscript
and Stephanie Meyer for technical assistance.
References
1.
Schessl J, Zou Y, McGrath MJ, et al. Proteomic identification of
FHL1 as the protein mutated in human reducing body myopathy.
J Clin Invest 2008;118:904 –912.
2.
Windpassinger C, Schoser B, Straub V, et al. An X-linked myopathy with postural muscle atrophy and generalized hypertrophy,
termed XMPMA, is caused by mutations in FHL1. Am J Hum
Genet 2008;82:88 –99.
3.
Quinzii CM, Vu TH, Min KC, et al. X-linked dominant scapuloperoneal myopathy is due to a mutation in the gene encoding
four-and-a-half-LIM protein 1. Am J Hum Genet 2008;82:
208 –213.
4.
Cowling BS, McGrath MJ, Nguyen MA, et al. Identification of
FHL1 as a regulator of skeletal muscle mass: implications for
human myopathy. J Cell Biol 2008;183:1033–1048.
5.
Voit T, Krogmann O, Lenard HG, et al. Emery-Dreifuss muscular
dystrophy: disease spectrum and differential diagnosis. Neuropediatrics 1988;19:62–71.
6.
Schmeichel KL, Beckerle MC. Molecular dissection of a LIM domain. Mol Biol Cell 1997;8:219 –230.
7.
Geier C, Gehmlich K, Ehler E, et al. Beyond the sarcomere:
CSRP3 mutations cause hypertrophic cardiomyopathy. Hum Mol
Genet 2008;17:2753–2765.
8.
Bonne G, Di Barletta MR, Varnous S, et al. Mutations in the
gene encoding lamin A/C cause autosomal dominant EmeryDreifuss muscular dystrophy. Nat Genet 1999;21:285–288.
9.
Ding L, Wang Z, Yan J, et al. Human four-and-a-half LIM family
members suppress tumor cell growth through a TGF-beta-like
signaling pathway. J Clin Invest 2009;119:349 –361.
10.
Spuler S, Kalbhenn T, Zabojszcza J, et al. Muscle and nerve
pathology in Dunnigan familial partial lipodystrophy. Neurology
2007;68:677– 683.
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