Long QT syndrome with mutations in three genes: A rare case.
Congenital long QT syndrome (LQTS) is a rare hereditary disease, with an incidence of 1 in 2000, characterized by prolonged ventricular repolarization and malignant ventricular tachyarrhythmias. We report the case of a 30-year-old woman, previously diagnosed with neurocardiogenic syncope, in whom LQTS was identified. The patient received an implantable cardioverter-defibrillator due to polymorphic ventricular tachycardia under beta-blocker therapy. Molecular genetic testing identified three mutations in heterozygosity in the KCNH2, KCNQ1 and SCN5A genes, which is a rare finding and is associated with worse prognosis.
Serviço de Cardiologia, Centro Hospitalar do Alto Ave, Guimarães, Portugal. Electronic address: a35904@hotmail.com.
Marina
M
Fernandes
Serviço de Cardiologia, Centro Hospitalar do Alto Ave, Guimarães, Portugal.
Sílvia
S
Martins Ribeiro
Serviço de Cardiologia, Centro Hospitalar do Alto Ave, Guimarães, Portugal.
Victor
V
Sanfins
Serviço de Cardiologia, Centro Hospitalar do Alto Ave, Guimarães, Portugal.
António
A
Lourenço
D000328:Adult; D000072237:ERG1 Potassium Channel / Q000235:genetics; D005260:Female; D006801:Humans; D051657:KCNQ1 Potassium Channel / Q000235:genetics; D008133:Long QT Syndrome / Q000235:genetics*; D009154:Mutation; D062554:NAV1.5 Voltage-Gated Sodium Channel / Q000235:genetics
D000072237:ERG1 Potassium Channel; C000606913:KCNH2 protein, human; D051657:KCNQ1 Potassium Channel; C496909:KCNQ1 protein, human; D062554:NAV1.5 Voltage-Gated Sodium Channel; C568320:SCN5A protein, human
Gene KCNH2; Gene KCNQ1; Gene SCN5A; KCNH2 gene; KCNQ1 gene; Long QT syndrome; Mutação trigénica; Polymorphic ventricular tachycardia; SCN5A gene; Síndrome QT longo; Taquicardia ventricular polimórfica; Triple mutation