RecruitingObservational Study to Describe Health-Related Quality of Life and Measure Disease Burden Among Patients With Long QT Syndrome Types (LQTS) 2 and 3This is a cross-sectional observational study designed to assess the disease burden and quality of life in individuals with LQTS 2 and 3. Each participant will answer each patient-reported outcome questionnaire only once over a 6-month period. The study will enroll up to 200 participants.