While LQT1 is transmitted in an autosomal dominant manner, homozygous or compound heterozygous mutations in KCNQ1 or the β-subunit KCNE1 cause the Jervell and Lange-Nielsen syndrome (JLNS), which has a autosomal recessive pattern of inheritance and is associated with severe life-threatening cardiac arrhythmias, a high risk of sudden death due to ventricular tachycardia, and congenital bilateral deafness [1, 106]. The gene discussed is KCNQ1; the disease is Jervell and Lange-Nielsen syndrome.