Interestingly, significantly lower KCNQ1 and KCNH2 mRNA levels were detected in male LQTS patients as compared to females (p = 0.0084; p = 0.035), possibly indicating an increased vulnerability in LQTS males to effects of NOS1AP loss-of-function sequence variants affecting repolarization reserve. Here, KCNH2 is linked to familial long QT syndrome.