Jervell and Lange-Nielsen syndrome with novel KCNQ1 and additional gene mutations

Abstract We encountered a boy with Jervell and Lange-Nielsen syndrome (JLNS) with compound heterozygous KCNQ1 mutations, maternal Trp248Phe and a novel paternal mutation, Leu347Arg. His father showed long QT (LQT) and arrhythmia. His mother was asymptomatic with no ECG abnormalities. The proband and his father had an additional mutation ( SNTA1 Thr372Met), which is reportedly related to SIDS. These results suggest that multiple gene mutations influence the phenotype of KCNQ1 mutation-related arrhythmia.