A 12-year-old girl presents with syncope during swimming at summer camp. ECG shows QTc 510 ms with broad-based monophasic T-waves. Exercise stress testing reveals paradoxical QT prolongation. Her mother has borderline QTc (470 ms) and a family history of sudden cardiac death during exercise in multiple relatives over three generations. Genetic testing confirms a heterozygous KCNQ1 mutation. The inheritance pattern marked **A** in the diagram is most consistent with which of the following?
Ready to test yourself?
Test your Medicine knowledge with AI-powered MCQs and detailed explanations — no signup required to try.
Sign up free and practice all 1 Long QT Syndrome Type 1 KCNQ1 MCQs with AI-powered explanations tailored to your performance.
Create Free Account