S38G genotype reportedly influences predisposition to both AF and LQTS (Fatini et al., 2006; Prystupa et al., 2006; Xu et al., 2008; Husser et al., 2009), and heart failure (Fatini et al., 2010), depending on factors including sex, age, BMI, diabetes, fibrinogen, hypercholesterolemia, hypertension, and another KCNE1 SNP (Friedlander et al., 2005). Here, KCNE1 is linked to atrial fibrillation.