HRCR Rare Diseases Article Collection
- Congenital long QT syndrome (LQT) is a potentially lethal hereditary arrhythmic disorder that can cause syncope and sudden cardiac death owing to polymorphic ventricular tachycardias in association with prolonged QT intervals in electrocardiograms (ECGs), termed as “torsades de pointes” (TdP). The prevalence of LQT is reported to be 1 in 2000, and genetic testing reveals mutations in cardiac ion channel–related genes in about 70% of the cases. Variants in the 3 genes, KCNQ1, KCNH2, and SCN5A, account for approximately 90% of LQT cases, referred to as LQT type 1, 2, and 3 (LQT1, LQT2, and LQT3), respectively.
- Life-threatening arrhythmias in apparently healthy individuals can be due to diverse heritable cardiac channelopathies.1 Ongoing advances revealing the underlying pathophysiology and genotype-phenotype associations are constantly evolving our approaches to diagnosis and management of these clinical entities.1–3 In some cases, initial diagnoses prove inaccurate over time, so routine reevaluation of each patient and family member remains an important element of care, with potentially life-altering ramifications.
- Long QT syndrome (LQTS) is an ion channelopathy that may cause life-threatening ventricular arrhythmias resulting in intrauterine death, cardiac arrest, or sudden death at any age.1–3 LQTS is often an inherited condition but may present as a de novo mutation, and its prevalence has been reported as high as 1:2000.4