Skin biopsies were obtained from two siblings, a 28-year old female asymptomatic LQT1 patient (QTc interval, 428 ms) and a 41-year old female symptomatic LQT1 patient (QTc interval, 456 ms), both with the KCNQ1 G589D mutation. This evidence concerns the gene KCNQ1 and long QT syndrome 1.