PRKAG2 encodes the γ2 regulatory subunit of the AMP-activated protein kinase AMPK and mutation-associated defects account for a cardiac syndrome triad consisting of familial ventricular preexcitation (Gollob et al., 2001), conduction system disease, and cardiac hypertrophy mimicking (HCM) (Gollob et al., 2002), with a significant proportion of those progressing to DCM. The gene discussed is PRKAG2; the disease is familial dilated cardiomyopathy.