Brief report : deletion of the dystrophin muscle-promoter region associated with X-linked dilated cardiomyopathy

Female carriers of Duchenne's muscular dystrophy may have cardiac symptoms as well10. [...]cardiomyopathy has been the presenting symptom of Becker's muscular dystrophy in rare instances,11-13 and cardiac failure is not necessarily a late feature of this disorder14. [...]he played competitive football. Because of the cardiomyopathy he was forced to abandon sports activities. [...]no clinical evidence of skeletal-muscle weakness was found in four affected male family members ranging in age from 23 to 36 years; two more male family members, who died of dilated cardiomyopathy at the ages of 29 and 44, were believed to be free from neuromuscular symptoms. Since creatine kinase levels were elevated in the affected men and signs of mild myopathy were found in the skeletal-muscle biopsy of the proband, the possibility remains that muscular weakness may develop in these patients later in life (and thus lead to a phenotype for mild Becker's dystrophy); even if this were the case, however, there would still be a dramatic discrepancy between the degree of skeletal- and cardiac-muscle involvement in this family. Cardiomyopathy is a common feature of Xp21 Duchenne's and Becker's muscular dystrophies, and deletions involving dystrophin exons 48, 45 through 53, and 48 and 49 have been reported in male patients who also had concomitant cardiomyopathy13,28. Since patients with identical deletions but without cardiomyopathy have been described as well,28 no firm correlation between the dystrophin genotype and (cardiac) phenotype has been established.