101. What is Jervell-Lange-Nielsen syndrome?

Jervell-Lange-Nielsen Syndrome is a genetic condition associated with a prolonged QT interval on the ECG and conginital hearing loss. A mutation of the cardiac potassium channel is responsible, specifically the KCNQ1 (90%) and KCNE1 (10%) genes. Jervell-Lange-Nielsen Syndrome is inherited in an autosomal recessive fashion. Treatment includes beta-blockers, however if syncope or sustained ventricular arrhythmias are present, an implantable cardioverter defibrillator (ICD) is indicated to prevent sudden cardiac death.