Twenty single nucleotide polymorphisms (SNPs) and their allelic frequencies in four genes that are responsible for familial long QT syndrome in the Japanese population.

We report here 20 single nucleotide polymorphisms (SNPs), including 10 novel ones, and their allelic frequencies detected in four genes that are known to be responsible for familial long QT syndrome in the Japanese population; 7 polymorphisms are in the KCNQ1 gene, 6 in the KCNH2 gene, 5 in the SCN5A gene, and 2 in the KCNE1 gene. These data will be of use for genetic association studies of acquired cardiac arrhythmias.