Centronuclear myopathy and cardiomyopathy requiring heart transplant.

Centronuclear myopathy has been extremely rarely associated with cardiomyopathy, which can lead to heart failure and premature death. We report the case of a 3.5-year-old girl with early-onset dilated cardiomyopathy, biventricular hypertrophy and histologic features suggestive of centronuclear myopathy. After unsuccessful medical treatment for heart failure, she underwent cardiac transplantation at the age of 4.5 years. Results of a skeletal muscle biopsy showed increased central nuclei and perinuclear vacuolations with aggregates of mitochondria. Examination of the heart at the time of transplantation confirmed a diagnosis of dilated cardiomyopathy. Histologic results revealed hypertrophic myocardiocytes, focal areas of infarction and endocardial fibroelastosis, most prominently in the left ventricle. Although cardiomyopathy is commonly associated with other childhood myopathies, to our knowledge, this is the youngest patient reported with centronuclear myopathy presenting with heart failure caused by cardiomyopathy, and the first patient to successfully undergo cardiac transplantation. One year after the heart transplant, there were no signs of rejection. We recommend detailed cardiac assessment with regular follow-up for children with histologic features consistent with centronuclear myopathy.