Dilated cardiomyopathy requiring cardiac transplantation as initial manifestation of Xp21 Becker type muscular dystrophy.

A neurologically asymptomatic 32-yr-old man recently transplanted for end-stage dilated cardiomyopathy presented with progressively increasing serum creatine kinase level (hyperCKemia) while receiving cyclosporin and simvastatine treatment. Revised family history led to suspicion of X-linked inherited myopathy, then confirmed by muscle biopsy findings showing myopathic dystrophic changes, a patchy distribution of immunoreactivity on the sarcolemma of several muscle fibres with anti-dystrophin antibodies and a double dystrophin band of normal and lower molecular weight on immunoblot analysis. A molecular genetic study demonstrated a deletion spanning over exons 45-47 at Xp21 locus. Routine neurological evaluation and currently available laboratory investigation may lead to early diagnosis of otherwise unrecognized Xp21 BMD among patients presenting with dilated cardiomyopathy alone, thus avoiding subsequent diagnostic difficulties.