The first three identified genes, which account for approximately 90% of genetically affected LQTS patients, encode α-subunits of cardiac voltage-gated ion channels: KCNQ1 for type-1 LQTS, KCNH2 for type-2 LQTS, and SCN5A for type-3 LQTS. The gene discussed is KCNQ1; the disease is familial long QT syndrome.