ACTC1 and left ventricular noncompaction: This pattern of clinical findings appears to represent an autosomal dominant disorder, distinct from previously reported Mendelian conditions due to ACTC1 variants which are characterized by cardiac abnormalities, including autosomal dominant atrial septal defects [MIM: 612794],44 dilated cardiomyopathy [MIM: 613424],45 hypertrophic cardiomyopathy [MIM: 612098],46 and left ventricular noncompaction [MIM: 613424]47).