Past research on HLHS has yielded very few high-confidence gene candidates that may contribute to HLHS, for example, NOTCH1, NKX2-5 and MYH6 have been implicated with HLHS (Elliott et al., 2003; Theis et al., 2015a; Theis et al., 2015b), but they are also associated with other CHDs. Here, NKX2-5 is linked to hypoplastic left heart syndrome.