Congenital long QT syndrome caused by the F275S KCNQ1 mutation: mechanism of impaired channel function.

Congenital long QT syndrome is characterized by a prolongation of ventricular repolarization and recurrent episodes of life-threatening ventricular tachyarrhythmias, often leading to sudden death. We previously identified a missense mutation F275S located within the S5 transmembrane domain of the KCNQ1 ion channel in a Chinese family with long QT syndrome. We used oocyte expression of the KCNQ1 polypeptide to study the effects of the F275S mutation on channel properties.

[Relationship between congenital long QT syndrome and Brugada syndrome gene mutation].

Objective: To investigate the molecular pathology in families with long QT syndrome (LQTS) including Jervell-Longe-Nielsen syndrome (JLNS) and Romano-ward syndrome (RWS) and Brugada syndrome (BS) in Chinese population.

Methods: Polymerase chain reaction and DNA sequencing were used to screen for KCNQ1, KCNH2, KCNE1, and SCN5A mutation.

Results: We identified a novel mutation N1774S in the SCN5A gene of the BS family, a novel mutation G314S in a RWS family which had also been found in Europe, North America, and Japan, and a single nucleotide polymorphisms (SNPs) G643S in the KCNQ1 of the JLNS family.

[Mutation analysis of a Chinese family with inherited long QT syndrome].

Objective: To identify the mutation of a Chinese family with inherited long QT syndrome(LQTS).

Methods: The disease-causing gene was tentatively determined in light of the clinical manifestations and electrophysiological properties, and then polymerase chain reaction and DNA sequencing were used for screening and identifying mutation.

Results: A missense mutation G940A(G314S) in the KCNQ1 gene was identified, which was the 'hot spot' of long QT syndrome mutation.

[PCR site-directed mutagenesis of long QT syndrome KCNQ1 gene in vitro].

To study PCR site-directed mutagenesis of long QT syndrome KCNQ1 gene in vitro. The site-directed mutagenesis of LQTS gene KCNQ1 was made by PCR. Two sets of primers were designed according to the sequence of KCNQ1 cDNA, and mismatch was introduced into primers.