Long QT syndrome (LQTS) is characterized by a prolongation of the QT segment on the electrocardiogram and can result in recurring syncopes or sudden cardiac arrest. Genetic analysis of LQTS focuses primarily on genes encoding for proteins that regulate the cardiac action potential. The MHI Molecular Diagnostic Laboratory reports the following genes in their first line testing: KCNH2 (25-40%), KCNQ1 (30-35%), SCN5A (5-10%), KCNE1 and KCNE2. The percentage indicates the frequency of variants found in these genes. If no variant is identified, ten other genes are analyzed as second line. Approximately 75% of LQTS cases have a genetic cause.
PMID: 21787999, 2011
PMID: 21459272, 2011
PMID: 26566530, 2015
Tested Genes :
| 1st intent | 2nd intent | 3rd intent |
|---|---|---|
| KCNE1 KCNE2 KCNH2 KCNQ1 SCN5A | AKAP9 ANK2 CACNA1C CALM1 CALM2 CAV3 KCNJ2 KCNJ5 SCN4B SNTA1 | None |