KCNQ1

(redirected from LQT)
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KCNQ1

A gene on chromosome 11p15.5 that encodes a voltage-gated potassium channel required for the repolarisation phase of the cardiac action potential. The KCNQ1 gene product can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3.
 
Molecular pathology
KCNQ1 mutations are associated with hereditary long QT syndrome/Romano-Ward syndrome, Jervell and Lange-Nielsen syndrome and familial atrial fibrillation.
References in periodicals archive ?
The prevalence of LQTS is estimated to be 1 in 2,000-5,000; however, the expressivity, or penetrance, of the syndrome is highly variable even within the same family.
Often the diagnosis of LQTS is not clear on initial evaluation, and a scoring system (Circulation 1993;88:782-4) is utilized to ascertain the probability of LQTS.
Although clinical parameters remain the cornerstone of risk stratification, advances in genotype-phenotype correlation in LQTS are improving personalized risk assessment.
The first gene for autosomal-dominant LQTS was mapped by Keating et al[20,21] to chromosome 11p15.
Since mutations in KVLQT1 were shown to cause LQTS (LQT1), mutations in minK were sought because mink plays an essential role in the development of [I.
Since LQTS is considered to be a disorder of abnormal repolarization, genes encoding ion channels or proteins modulating channel function were considered candidates for LQTS.
The positional candidate gene approach was also used to establish that the gene responsible for chromosome 3-linked LQTS (LQT3) is the cardiac sodium channel gene SCN5A.
The specific mechanism causing the differences between LQTS and Brugada syndrome is not known.
Three missense mutations associated with LQTS and ventricular fibrillation were identified in KCNE2 by Abbott et al,[30] and biophysical analysis demonstrated that these mutants form channels that open slowly and close rapidly, thus diminishing potassium currents.
GENETICS AND PHYSIOLOGY OF AUTOSOMAL-RECESSIVE LQTS (JLNS)
Ks] current, whether it occurs due to homozygous mutations in KVLQT1 or minK result in LQTS and deafness.