A case of an infant with compound heterozygous mutations for hypertrophic cardiomyopathy producing a phenotype of left ventricular noncompaction

A male infant was born to a 38-year-old G1P0 mother with hypertrophic cardiomyopathy (HCM). Fetal echocardiography was suspicious for HCM; however, postnatal echocardiography demonstrated features consistent with left ventricular noncompaction (LVNC). The infant was initially stable but presented at 2 months of age in cardiogenic shock. On genetic analysis, both parents were heterozygous for mutations associated with HCM. The proband was a compound heterozygote. This case, in which 2 mutations for HCM produced a phenotype of LVNC, has not been demonstrated in humans and raises the question of whether HCM and LVNC represent a continuum of pathologic processes.