Expression-levels of KCNQ1 and KCNH2 have been shown to differ in an age-and-sex dependent manner when studied in independent LQTS families (n = 163, whereof 98 LQTS patients), including significantly different mRNA levels in children, adults and adults over the age of 55 years [35]. The gene discussed is KCNQ1; the disease is familial long QT syndrome.