KCNE1 and Jervell and Lange-Nielsen syndrome: An international consortium of 26 centers identified 89 probands with possible LQT5, 140 additional carrier relatives, and 19 cases of Jervell-Lange-Nielsen Syndrome (MIM: 612347) attributed to homozygous or compound heterozygous KCNE1 loss of function variants.17 The commonest mutation was p.Asp76Asn, with 35 probands and 63 carrier relatives.