Genetic analysis is very important for identifying all mutation carriers within the LQTS family. Once identified, silent carriers of LQTS genetic defects may be treated with beta-blockers for prophylaxis of life-threatening arrhythmias. Furthermore, silent mutation carriers should receive genetic counseling to learn about the risk of transmitting LQTS to offspring. In patients affects by LQTS, genetic analysis is useful for risk stratification and for making therapeutic decisions. Risk Stratification *Genetic testing is often useful in probands with a clinical diagnosis of LQTS to provide more accurate risk stratification and to guide therapeutic strategies. *It has been shown that the interplay between genetic defect, QT duration, and gender may provide an algorithm for risk stratification. Genetic testing that can detect a mutation which may cause cardiac channelopathies, rare, potentially lethal heart conditions. The tests can reduce uncertainty and find the specific causes of cardiac channelopathies, the test can: *Help diagnose a patient's disease *Guide treatment options *Determine whether family members are at risk Patients presenting with: -Unexplained syncope -Onset of symptoms typically occurs during childhood and adolescence -Family Hx of sudden cardiac death -Unexplained VT/VF or TdP -Prolonged QT interval KCNQ1 (LQT1) KCNH2 (LQT1) SCN5A (LQT3) KCNE1 (LQTS) KCNE2 (LQT6) Please print, complete and submit the Test Requisition and Informed Consent for Testing from PGxHEALTH with the A-1a Miscellaneous Request.