[A two-year-old clinically manifesting carrier of Duchenne muscular dystrophy]

A two-year-old symptomatic carrier of Duchenne muscular dystrophy (DMD) confirmed by dystrophin immunohistochemical study was reported. She had mild proximal muscular weakness and elevated serum creatine kinase (CK) level. There were no family members of DMD. CT examination revealed low density areas in the muscles similar to that seen in the early stage of DMD. Biopsied specimen of muscle showed myopathic changes with necrotic and regenerating fibers. The immunohistochemical study using an antiserum against dystrophin showed the mosaic expression of the surface membrane, with positive and negative patches. Accordingly, she was strongly suggested to be a DMD carrier. This case shows that dystrophin immunohistochemistry is useful for diagnosis of a DMD carrier without affected family members.