Congenital myopathy with type II muscle fiber hypoplasia.
We examined a 14-month-old boy with severe muscular hypotonia and weakness. Loss of tendon reflexes were noted at age 2 months. Right-sided heart failure and dyspnea during sleep developed at age 4 months. Muscle biopsy revealed selective hypoplasia of type II fibers and normal type I fibers. Intercostal and diaphragmatic muscles showed similar changes at necropsy and probably accented the respiratory failure.
D006801:Humans; D007223:Infant; D008297:Male; D009133:Muscular Atrophy / Q000151:congenital / Q000473:pathology*