We have recently shown that family members carrying these mutations share a common haplotype that is specific for each mutation[26] [Abstract number 154:Winbo A. Stattin E.L. Nordin C. Persson J. Diamant U.B. Jensen S.M. Rydberg A. Origin, genotype and clinical phenotype of the Long QT Syndrome R518X/KCNQ1 mutation in Sweden. Here, KCNQ1 is linked to Prolonged QT interval.