Year: 1998
Type: article
Study design: Observational Study
Abstract: BACKGROUND: The congenital long-QT syndrome, caused by mutations in cardiac potassium-channel genes (KVLQT1 at the LQT1 locus and HERG at the LQT2 locus) and the sodium-channel gene (SCN5A at the LQT3 locus), has distinct repolarization patterns on electrocardiography, but it is not known whether the genotype influences the clinical course of the disease. METHODS: We determined the genotypes of 541 of 1378 members of 38 families enrolled in the International Long-QT Syndrome Registry: 112 had mutations at the LQT1 locus, 72 had mutations at the LQT2 locus, and 62 had mutations at the LQT3 locus. We determined the cumulative probability and lethality of cardiac events (syncope, aborted cardiac arrest, or sudden death) occurring from birth through the age of 40 years according to genotype in the 246 gene carriers and in all 1378 members of the families studied. RESULTS: The frequency of cardiac events was higher among subjects with mutations at the LQT1 locus (63 percent) or the LQT2 locus (46 percent) than among subjects with mutations at the LQT3 locus (18 percent) (P<0.001 for the comparison of all three groups). In a multivariate Cox analysis, the genotype and the QT interval corrected for heart rate were significant independent predictors of a first cardiac event. The cumulative mortality through the age of 40 among members of the three groups of families studied was similar; however, the likelihood of dying during a cardiac event was significantly higher (P<0.001) among families with mutations at the LQT3 locus (20 percent) than among those with mutations at the LQT1 locus (4 percent) or the LQT2 locus (4 percent). CONCLUSIONS: The genotype of the long-QT syndrome influences the clinical course. The risk of cardiac events is significantly higher among subjects with mutations at the LQT1 or LQT2 locus than among those with mutations at the LQT3 locus. Although cumulative mortality is similar regardless of the genotype, the percentage of cardiac events that are lethal is significantly higher in families with mutations at the LQT3 locus.
Source: New England Journal of Medicine
Authors: Wojciech Zareba, Arthur J. Moss, Peter J. Schwartz, G. Michael Vincent, Jennifer L. Robinson, Silvia G. Priori, Jesaia Benhorin, Emanuela H. Locati, Jeffrey A. Towbin, Mark T. Keating, Michael H. Lehmann, W. Jackson Hall, Mark L. Andrews, Carlo Napolitano, Katherine Timothy, Li Zhang, Aharon Medina, Jean W. MacCluer
Institutions: University of Rochester Medicine, University of Rochester, University of Milan, University of Pavia, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Policlinico San Matteo Fondazione, LDS Hospital, Fondazione Salvatore Maugeri, Bikur Cholim Hospital, University of Perugia, Baylor College of Medicine, Texas Children's Hospital, Howard Hughes Medical Institute, University of Utah, Sinai Hospital
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2334363451