Most cases of WPW have been linked to pathogenic variants in PRKAG2 or MYH6, glycogen storage disorders, mitochondrial syndromes, or congenital heart diseases such as septal defects, Ebstein malformation of the tricuspid valve, or HCM (Bowles et al., 2015; Ehtisham & Watkins, 2005). The gene discussed is MYH6; the disease is Ebstein anomaly of the tricuspid valve.