Facioscapulohumeral muscular dystrophy presenting with hypertrophic cardiomyopathy: a case study.
ABSTRACT Only three facioscapulohumeral muscular dystrophy (FSHD) patients have been reported to have cardiomyopathy. An asymptomatic 38-year-old man was incidentally found to have electrocardiographic abnormalities. His echocardiogram demonstrated mild dilatation of the left ventricle and poor contractility. Cardiac histopathology indicated hypertrophic cardiomyopathy. Later he developed muscle weakness in the right arm. Scapular winging and asymmetrical facial weakness were evident. Muscle biopsy at the age of 44 years showed myopathic changes consistent with FSHD. His daughter had symptoms of infantile FSHD, which was genetically confirmed. This is the first report of an FSHD patient with biopsy-proven cardiomyopathy.
Journal of the Neurological Sciences 12/2014; 348(1-2). DOI:10.1016/j.jns.2014.12.009 · 2.26 Impact Factor
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ABSTRACT: Facioscapulohumeral muscular dystrophy cases with facial weakness before the age of 5 and signs of shoulder weakness by the age of 10 are defined as early onset. Contraction of the D4Z4 repeat on chromosome 4q35 is causally related to facioscapulohumeral muscular dystrophy type 1, and the residual size of the D4Z4 repeat shows a roughly inverse correlation with the severity of the disease. Contraction of the D4Z4 repeat on chromosome 4q35 is believed to induce a local change in chromatin structure and consequent transcriptional deregulation of 4qter genes. We present early-onset cases in the Polish population that amounted to 21% of our total population with facioscapulohumeral muscular dystrophy. More than 27% of them presented with severe phenotypes (wheelchair dependency). The residual D4Z4 repeat sizes ranged from 1 to 4 units. In addition, even within early-onset facioscapulohumeral muscular dystrophy type 1 phenotypes, some cases had uncommon features (head drop, early disabling contractures, progressive ptosis, and respiratory insufficiency and cardiomyopathy).Journal of child neurology 04/2014; DOI:10.1177/0883073814528281 · 1.67 Impact Factor
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ABSTRACT: Facioscapulohumeral muscular dystrophy (FSHD) is a progressive myopathy with a relatively late age of onset (usually in the late teens) compared with Duchenne and many other muscular dystrophies. The current FSHD disease model postulates that contraction of the D4Z4 array at chromosome 4q35 leads to a more open chromatin conformation in that region and allows transcription of the DUX4 gene. DUX4 mRNA is stable only when transcribed from certain haplotypes that contain a polyadenylation signal. DUX4 protein is hypothesized to cause FSHD by mediating cytotoxicity and impairing skeletal muscle differentiation. We recently showed in a cell culture model that DUX4 expression is regulated by telomere length, suggesting that telomere shortening during aging may be partially responsible for the delayed onset and progressive nature of FSHD. We here put our data in the context of other recent findings arguing that progressive telomere shortening may play a critical role in FSHD but is not the whole story and that the current disease model needs additional refinement.