A Japanese boy with nemaline myopathy diagnosed at three years of age and complicated by severe respiratory failure at 8 years is reported from the Division of Child Neurology, National Center Hospital for Mental, Nervous, and Muscular Disorders, Kodaira, Tokyo, Japan. The histologic findings of the respiratory muscles obtained during thoracic surgery for pneumothorax showed marked variation in fiber size with increase in fibrous tissue, type II fiber deficiency, elevated acid phosphatase activity, and disorganized intermyofibrillar network. Truncal and biceps muscles showed little variation in fiber size, numerous nemaline bodies and type I fiber predominance. The sudden onset of severe respiratory failure was related to the preferential and progressive involvement of the respiratory muscles. 
COMMENT. Severe respiratory insufficiency is an uncommon development in nemaline myopathy, but a frequent complication of Duchenne’s muscular dystrophy. Miller RG et al from the Children’s Hospital of San Francisco have made serial measures of respiratory function in 17 patients with Duchenne’s muscular dystrophy who underwent segmental spinal fusion and in 22 patients without operations. Declining respiratory function was observed in both groups, but operated patients showed improved sitting comfort.