Influence of the genotype on the clinical course of the long-QT syndrome

Genetic mutations in genes related to potassium channels in the heart may increase the risk of fatal cardiac events in patients with long-QT syndrome. Long-QT syndrome is a disorder of heart rhythm that increases the risk of fainting, ventricular tachycardia, and sudden death. Researchers examined the genetic profile of 541 people with the disorder, and found that particular genetic mutations were present in 246 people. Those with the mutations were 4-20% more likely to suffer a fatal heart disturbance than people without the mutations.