MYH6 and hypoplastic left heart syndrome: Variants in genes such as GJA1 (7), NKX2.5 (10), NOTCH1 (11), and most recently, myosin heavy chain 6 (MYH6) (38) as well as observations of syndromic or rare copy number variants in cardiogenic genes (13, 14, 39, 41) have been associated with HLHS.