A progressive congenital myopathy. Initial involvement of the diaphragm with type I muscle fiber atrophy.

An uncommon case of initial respiratory distress during the first months of life as the result of bilateral diaphragmatic weakness is presented. The biopsy and necropsy findings show a progressive congenital myopathy with type I muscle fiber atrophy and predominant involvement of the respiratory muscles. The lesions, observed in the central nervous system are due to the severe hypoxia. The morphological findings are discussed in relation to the etiology and the clinical picture of the disease.