Congenital long QT syndrome of particularly malignant course connected with so far unknown mutation in the sodium channel SCN5A gene

This article presents the case of a 35 year-old male with long QT syndrome (LQTS) who suffered from sudden cardiac arrest. Even though asymptomatic LQTS had been diagnosed, the patient had not undergone any medical treatment. His two daughters, aged four and seven, were also diagnosed with LQTS. A new, previously unknown, mutation of the SCN5A gene has been found in the family. The older daughter died suddenly before implantable cardioverterdefibrillator (ICD) implantation, but the father and the younger daughter have been implanted with ICDs.