Congenital muscular dystrophy (CMD) - a collagen formative disease?

Muscle biopsies of 5 patients with congenital muscular dystrophy (CMD) (8 months to 3 years old) were examined by electron microscopy to determine ultrastructural abnormalities of the muscle as well as of the connective tissue cells. Two populations of muscle fibers were observed in each biopsy. Besides muscle fibers with normal or enlarged diameters there were frequently very small muscle cells indicating immaturity. The most interesting findings in each biopsy were myofibroblast-like cells exhibiting active protein synthesis. Large amounts of collagen fibrils with abnormal diameters as well as accumulation of elastic fibrils within the endomysium in CMD suggest abnormalities in collagen synthesis.