Single-gene variants can cause syndromic CHD (e.g., Noonan syndrome, Holt-Oram syndrome, Alagille syndrome) as well as isolated genetic CHD (e.g., variants in NOTCH1 and FLT4) (Pierpont et al., 2007; Nees and Chung, 2020). This evidence concerns the gene FLT4 and coronary artery disorder.