[Distal myopathy with rimmed vacuoles and sudden death--report of two siblings]

We describe two siblings with distal myopathy with rimmed vacuoles, who died suddenly presumably due to fatal arrhythmia. Case 1. A 26-year-old man with a 4 year-history of progressive muscle weakness and wasting was hospitalized in April, 1989. The family history showed that his younger brother had the same disease, but his parents, not consanguineous, and other family members had no neuromuscular diseases. On admission, neurologic examination showed muscle weakness and atrophy in the distal portions of four extremities. No myotonia or fasciculation was present. The deep tendon reflexes were absent except diminished bilateral PTR. Sensation and co-ordination were normal. The creatinine kinase (CK) level was moderately elevated to 691 IU/l, and the aldolase mildly to 6.9 IU/l. Normal laboratory values included serum electrolytes, glucose and thyroid function study. An ischemic forearm exercise test revealed a normal rise in serum lactate and pyruvate concentrations. The glucose response after glucagon was normal in the fasting state. An electrocardiogram and chest film were normal. An electromyogram revealed myopathic changes with mild neuropathic changes, including positive sharp waves and fibrillation potentials at rest. The muscle biopsy specimen from the left anterior tibial muscle showed scattered fibers with rimmed vacuoles and moderate variation in fiber size. Neither fiber necrosis nor inflammatory cellular infiltration was seen. Regenerating fiber was not present. An electron microscopic examination showed numerous lamellar bodies of various size. Nerve biopsy was normal. He was diagnosed as having distal myopathy with rimmed vacuoles. Muscle weakness progressed gradually over the next two years, but his general condition was good. He asked to receive the corticosteroid therapy, and rehospitalized.(ABSTRACT TRUNCATED AT 250 WORDS)