2006, Number 3
<< Back Next >>
Arch Cardiol Mex 2006; 76 (3)
KCNQ1 (KvLQT1) missense mutation causing congenital long QT syndrome (Jervell, Lange-Nielsen) in a Mexican family
Márquez MF, Ramos-Kuri M, Hernández-Pacheco G, Estrada J, Fabregat JR, Pérez-Vielma N, Gómez-Flores J, González-Hermosillo A, Cárdenas M, Vargas-Alarcón G
Language: Spanish
References: 20
Page: 257-262
PDF size: 169.28 Kb.
ABSTRACT
Background: Long QT syndromes (LQTS) are
inherited cardiac disorders caused by mutations
in the genes that encode sodium or potassium
transmembrane ion channel proteins. More than
200 mutations, in at least six genes, have been
found in these patients. The Jervell and Lange-
Nielsen (JLN) syndrome is the recessive form of
the disease and is associated with deafness.
Few families with JLN syndrome and genetic
studies are reported in the literature.
Methods:
The KCNQ1 (KvLQT1) gene in a Mexican family
with Jervell-Lange-Nielsen long QT syndrome
was analyzed using an automated sequence
method.
Results: A missense mutation was
found in the three affected individuals. This mutation
is associated with complete loss of channel
function. Correlation with the phenotype
showed a prolonged QTc interval and deafness
in the two siblings homozygous to the mutation. The mother, who was heterozygous for the mutation,
also had prolonged QTc interval without
deafness. The father and younger brother had
normal QTc intervals. The mutation was not found
in 50 healthy controls studied.
Conclusions: We
describe for the first time a mutation in the
KCNQ1 gene in a Mexican family with JLN long
QT syndrome. This mutation produces an amino
acid change (Gly-Arg) at protein level at the 168
residue. This mutation has been previously reported
in Caucasian families with LQTS.
REFERENCES
VINCENT GM: Long QT syndrome. Cardiology Clinics 2000; 18: 309-325.
JERVELL A, LANGE-NIELSEN F: Congenital deaf-mutism. Functional heart decrease with prolongation of the QT interval and sudden death. Am Heart J. 1957; 54: 59-68.
HERBERT E, TRUSZ-GLUZA M, MORIC E, SMILOWSKADZIELICKA E, MAZUREK U, WILCZOK T: KCNQ1 gene mutations and the respective genotype-phenotype correlations in the long QT syndrome. Med Sci Monit 2002; 8: 240-248.
SPLAWSKI I, SHEN J, TIMOTHY KW, LEHMANN MH, PRIORI S, ROBINSON JL, ET AL: Spectrum of mutations in long-QT syndrome genes KVLQT1, HERG, SCN5A, KCNE1 and KCNE2. Circulation 2000; 102: 1178-1185.
DAVIS RW, THOMAS M, CAMERON J, ST JOHN TP, PADGETT RA: Rapid DNA isolation for enzymatic 262 MF Márquez y cols. www.archcardiolmex.org.mx and hybridization analysis. Methods Enzymol 1980; 65: 404-411.
SPLAWSKI I, SHEN J, TIMOTHY KW, VINCENT GM, LEHMANN MH, KEATING MT: Genomic structure of three long QT syndrome genes: KVLQT1, HERG and KCNE1. Genomics 1998; 51: 86-97.
MOSS AJ, ZAREBA W, BENHORIN J, LOCATI EH, HALL WJ, ROBINSON JL, ET AL: ECG T-wave patterns in genetically distinct forms of the hereditary long QT syndrome. Circulation 1995; 92: 2929-2934.
HERMOSILLO AG: El electrocardiograma en las canalopatías. Arch Cardiol Mex. 2004; 74(suppl 1): 579-583.
DUMAINE R, ANTZELEVITCH C: Molecular mechanism underlying the long QT syndrome. Curr Opin Cardiol. 2002; 17: 36-42.
CANUN S, PÉREZ N, BEIRANA LG: Andersen syndrome autosomal dominant in three generations. Am J Med Genet 1999; 85: 147-156.
ROBERTS R, BRUGADA R: Genetics and arrhythmias. Annu Rev Med 2003; 54: 257-267.
VATTA M, LI H, TOWBIN JA: Molecular biology of arrhythmic syndromes. Curr Opin Cardiol 2000; 15: 12-22.
FOZZARD HA: Cardiac ion channels. En: SPOONER PM, ROSEN MR: Foundations of cardiac arrhythmias. Basic concepts and clinical approaches. Marcel Dekker, Inc. New York 2001: 43-72.
PRIORI SG, NAPOLITANO C, SCHWARTZ PJ, GRILLO M, BLOISE R, ET AL: Association of long QT syndrome loci and cardiac events among patients treated with beta-blockers. JAMA 2004; 292: 1341-1344.
MATHEWS EC, BLOUNT AW, TOWNSEND JI: Q-T prolongation and ventricular arrhythmias, with and without deafness, in the same family. Am J Cardiol 1972; 29: 702-711.
DONGER C, DENJOY I, BERTHET M, NEYROUD N, CRUAUD C, BENNACEUR M, ET AL: KVLQT1 C-terminal missense mutation causes a forme fruste long- QT syndrome. Circulation 1997; 96: 2778-2781.
WESTENSKOW P, SPLAWSKI I, TIMOTHY KW, KEATING MT, SANGUINETTI MC: Compound mutations. A common cause of severe long-QT syndrome. Circulation 2004; 109: 1834-1841.
LISKER R, PÉREZ-BRICEÑO R, GRANADOS J, BABINSKY V: Gene frequencies and admixture estimates in a Mexican City population. Am J Physical Anthropol 1986; 71: 203-207.
LISKER R, PÉREZ-BRICEÑO R, GRANADOS J, BABINSKY V, DE RUBENS J, ARMENDARES S, ET AL: Gene frequencies and admixture estimates in the State of Puebla, Mexico. Am J Physical Anthropol 1987; 6: 331-335.
LISKER R, RAMIREZ E, PÉREZ-BRICEÑO R, GRANADOS J, BABINSKY V: Gene frequencies and admixture estimates in four Mexican Urban Centers. Hum Biology 1990; 62: 791-801.