Disease-causing gene mutations have been identified in 75% of cases of LQTs andare further divided into subtypes based on the underlying genetic disruption [2].Genes encoding for cardiac ion channels, with KCNQ1, KCHN2, SCN5A represent mostof the common pathogenic variants in LQTs subtypes 1,2 and 3 respectively.Despite the growing insights into genotype-phenotype correlation forgene-specific therapies in LQTs, varying degrees of penetrance and phenotypicexpression pose a significant diagnostic challenge [3]. The gene discussed is KCNQ1; the disease is familial long QT syndrome.