Résumé :
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Introduction: Mutations in the LMNA gene have been associated with a heterogeneous series of human diseases. The neuromuscular phenotypes may involve the skeletal muscle, heart or both. Muscle morphology usually shows only mild myopathic or non-specific changes but exceptionally, myofibrillar changes have been described. Objectives: To describe a patient with adult-onset cardiomyopathy due to a novel unreported lamin A/C gene mutation Patient: A 53–year-old woman was referred because of sudden disarthria and right hemiparesia which spontaneously recovered in a few days. She had no vascular risk factors. Brain MRI confirmed the existence of two recent ischemic lesions one in cerebellum and another one in the pons. Angio-MRI was normal. The G20210A mutation in prothrombin (factor II) was detected. Holter-ECG showed frequent extrasystoles. Echocardiogram was normal. Several members of her father’s family, including her father, experienced cardiac arrhythmias or stroke and sudden death between the ages of 40 and 60. She reported slight paravertebral and pelvic muscle weakness from her forties Clinical examination showed a 4/5 in MRC scale weakness in paravertebral and pelvic muscles without contractures. Adipose tissue distribution was normal. ENG-EMG study was normal. The serum CK level was 154U/L (n.v. <190U/L). Muscle MRI demonstrated striking atrophy of paravertebral muscles, glutei and posterior group of tights and less prominent changes in quadriceps, sparing the rectus femoris. At mild-calf level, atrophy of the soleus and the medial head of gastrocnemius were evident. Muscle biopsy of the vastus lateralis showed myopathic changes with variation in the fiber size, and scarce fibers containing basophilic, desmin-positive subsarcolemmal deposits. Analysis of the lamin A/C gene detected a novel heterozygous mutation Asp357Asn in a highly conserved region of the gene. Conclusion: The novel Asp357Asn mutation in lamin A/C gene manifests as an adult-onset cardiomyopathy with frequent sudden death and mild proximal myopathy.
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