[Unknown cause of familial neuromuscular disease with infiltration of cytotoxic/suppressor T cells].
We report two brothers, aged 68 and 61 years respectively, who had an unclassified familial neuromuscular disease with infiltration of cytotoxic/suppressor T cells in muscle biopsies. The elder brother was in good health and active during child and adulthood until the age of 65 when muscle atrophy in the quadriceps muscle was noted. His muscle weakness and atrophy progressed relatively rapidly in the course of a few years. The muscle symptoms predominated in the under extremities at the initial stage, later to be generalized, sparing the facial muscles. The serum creatine kinase (CK) was 145 mu/ml (normal 5-80 mu/ml). EMG revealed myopathic changes. A biopsy taken from biceps muscle showed extensive inflammatory cellular infiltrations among fibers and in the perimysium. The infiltrated cells were identified to be cytotoxic/suppressor T cells. The younger brother first noticed diminished bulk in quadriceps muscle bilaterally at the age of 59. The muscle symptoms were similar to those seen in his brother. Serum CK was 520 mu/ml. EMG showed myopathic changes except for fibrillation potentials in the biceps. A biopsy taken from quadriceps muscle revealed the similar findings of his brother. The classification of these cases is a controversial subjects. We differentiated quadriceps myopathy, limb-girdle muscular dystrophy and myositis, which we couldn't classify. So at this point we reported these cases as unknown cause of familial neuromuscular disease.