A 31-year-old woman experiencad difficulty in climbing upstairs at the age of 16. Her symptom developed gradually, so she visited our hospital at the age of 18. At that time, mild to moderate muscle weakness was pbsreved in the anterior tibial and gastrocnemius muscle, respectively. Moderate muscle atrophy was obsersued in the gastrocnemius muscles, predomi-nantly on the right side. Her serum CK was 9000 U/I and electromyography showed a myogenic change in the gastroenemius muscles. Her muscle CT scan showed low density areas in the atrophic gastrocnemius muscles. A muscle biopsy from the left gastrocnemius muscle revealed a moderate variation of fiber-size and scattered necrotic and regenerating myof ibers. Her elder brother showed the same neurological symptom which indicated autosomal recessve Inheritance. The patient was diagnosed as having Miyoshi type distal muscular dystrphy. One year later, proximal muscle weakness and atrophy was noticed in her lower extremities. Subseguenthy Then, her symptoms continued leveling gradually, and muscle atrophy and weakness had spred by the age of 31. Recently dysferlin has been identified as a causative protein of Miyoshi type distal muscular dystrophy, as well as limb-girdle muscular dystrophy type 2B. Dysf elrin gene analysis in this case showed G to A point mutation at mucleotide No 6508 in exon 51, which resulted in the alteration of amino acid, je typtophan to stop colon. This mutation site was very close to the C-treminus. Nishida
et al presented an interesting report in which a patient with Miyoshi type distal muscular dystrophy whose initial symptom was limited to the distal muscle at first, developed proximal muscle weakness and atrophy. Subseguenthy Nishida
et al proposed a new clinical entity of “distal limb-girdle type muscular dystrophy”Therefore, this present case with mutation of the dysferlin gene was consistent with the clinical entity, “distal limb-girdle type muscular dystrophy”. At present the relationship between the characteristic mutation site in this case and the phenotype is not defined. Further accumulation of similar cases and the mutation analysisi of these cases will shed light on the mechanism of peculiar muscular involvement of these cases.
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