DYSTROPHIN GENE ABNORMALITIES IN 2 PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY

Two new cases of dilated cardiomyopathy (DC) caused by dystrophinopath y are reported. One patient, a 21 year old man, had a family history o f X linked DC, while the other, a 52 year old man, had sporadic diseas e. Each had abnormal dystrophin immunostaining in muscle or cardiac bi opsy specimens, but neither had muscle weakness. Serum creatine kinase activity was raised only in the patient with familial disease. Analys is of dystrophin gene mutations showed a deletion of exons 48-49 in th e patient with familial DC and of exons 49-51 in the other. Dystrophin transcription in cardiac tissue from the patient with sporadic diseas e showed abundant expression, predominantly of the muscle isoform. Thi s study, together with previous reports, suggests that some patients w ith DC have a dystrophinopathy that can be diagnosed using a combinati on of biochemical and genetic analyses.