Unusual association of hypertrophic cardiomyopathy with complete atrioventricular canal defect and Down syndrome

Hypertrophic cardiomyopathy typically presents as an isolated cardiac lesion. Transient hypertrophic cardiomyopathy in infancy has been described as a result of exposure to maternal metabolic disorders or to corticosteroids. In addition, hypertrophic cardiomyopathy has been described in association with genetic syndromes and, in rare cases, as a primary lesion associated with other congenital heart defects. We describe the unusual association of hypertrophic cardiomyopathy and complete atrioventricular canal defect in an infant with trisomy 21.