CLINICAL AND GENETIC CHARACTERISTICS OF LONG QT SYNDROME: A SINGLE-CENTER ANALYSIS

Congenital Long QT Syndrome (LQTS) is a genetic di­sorder affecting cardiac ion channels, leading to prolon­ged ventricular repolarization and an increased risk of life-threatening arrhythmias such as Torsades de Pointes and sudden cardiac death (SCD). This study aimed to evaluate the clinical and genetic characteristics of pedi­atric LQTS patients at a single center, identifying com­mon genetic variants, their phenotypic associations, and implications for management. A retrospective analysis was performed on 50 pediatric patients with LQTS dia­gnosed between 2006 and 2024.

The study cohort consisted of 56% males and 44% females, with a mean age of 12.1years (3.64). Me­dian QTc interval was 461 ms (450-492). Genetic tes­ting identified mutations in 34% of patients, including KCNQ1 (64%), KCNH2 (6%), and SCN5A (6%). QTc interval was significantly longer in the pathogenic muta­tions group (p<0.05) and mutations correlated with QTc length (r=0.403, p=0.004). Beta-blockers were prescribed for 28% with longer QTc in this group (p=0.011). This study highlights the phenotypic and genotypic diversity of LQTS, emphasizing the role of genetic testing in risk stratification.