Desmin-related restrictive cardiomyopathy in a pediatric patient: a case report.

Restrictive cardiomyopathies in the pediatric population have diverse etiologies, including storage diseases like hemosiderosis, glycogenoses and desmin with its associated proteins. Desmin-related myopathy is a rare familial disorder of the cardiac and skeletal muscle characterized by intrasarcoplasmic accumulation of desmin-reactive deposits in the muscle cells. The patients commonly present with cardiac involvement such as conduction blocks and/or restrictive cardiomyopathy. Diagnosis of desmin cardiomyopathy depends on light microscopic evaluation of endomyocardial biopsy, where abnormal deposition of desmin can be documented on immunohistochemistry and ultrastructural examination. The index report presents the clinical, light microscopic and ultrastructural findings of desmin cardiomyopathy.