Estimation of Incidence and Prevalence of Pediatric Channelopathies in a Mediterranean Population Based on a Single-Center, Retrospective Analysis

Background: Channelopathies represent a heterogeneous group of rare inherited cardiac diseases associated with life-threatening arrhythmias. Our knowledge of their epidemiology in childhood is limited. The aim of this study is to evaluate the epidemiology of pediatric channelopathies on a Mediterranean island (Crete, Greece). Methods: Retrospective study of children < 18 years followed in the Regional Tertiary Pediatric Cardiology Unit during a 24-year period (2002–2025) and meeting the disease-specific diagnostic criteria. Results: A total of 43 children (32 families) were enrolled, corresponding to an average annual incidence of 1.43 (95% C.I.: 1.03–1.92) and a cumulative prevalence of 31.1 (95% C.I.: 22.1–42.5) cases per 100, 000 children, with significant regional incidence differences. Long QT syndrome (n = 38) was predominant; rare cases of Brugada syndrome (n = 3) and Catecholaminergic polymorphic tachycardia (n = 2) were recorded. The diagnosis was based on symptomatic presentation (n = 15, 35%), while asymptomatic patients (n = 28, 65%) were diagnosed during cascade family screening (n = 22, 51%) and preparticipation screening (n = 6, 14%). They represented the first diagnosis within affected families (index cases) in 21/43 (49%) of cases. Genetic testing was performed in 35/43 (81%) channelopathy cases and it was positive in 33/43 (77%) of them, specifically in 30 out of 38 (79%) LQT cases with a genotype of LQT2 in 15 (39%), LQT1 in 10 (26%), LQT3 in one (3%) and LQT5 in two (5%) cases. Conclusions: The incidence of pediatric channelopathies on the Mediterranean island of Crete seems comparable to that reported in the literature, with regional clusters of significantly increased incidence. Further study of the epidemiology of pediatric channelopathies is needed, to document any regional or ethnic differences and for the best design of large-scale screening programs.