This is the first autopsy case report of a syndrome with autosomal recessive inheritance, muscular atrophy, contracture, skin eruption, hyper γ-globulinemia, decreased subcutaneous fat, mental retardation and abnormal ECG findings. Skeletal muscles showed severe, discrete, multifocal muscular fibrosis which replaced several primary fasciculi. The tongue, heart and extraocular muscles showed identical but less severe findings. In the involved muscle fasciculi, veins and venules as well as arteries and arterioles showed medial hyperplasia and luminal constriction. Degeneration of endothelial cells of arterioles and narrowing of the lumen of terminal arterioles by the debris were observed. The peripheral nerves in the muscles were relatively well preserved. The correlation and pathogenesis of these findings are discussed.