J 2021

Long-QT founder variant T309I-Kv7.1 with dominant negative pattern may predispose delayed afterdepolarizations under β-adrenergic stimulation

SYNKOVÁ, Iva, Markéta BÉBAROVÁ, Irena ANDRŠOVÁ, Larisa CHMELIKOVA, Olga ŠVECOVÁ et. al.

Basic information

Original name

Long-QT founder variant T309I-Kv7.1 with dominant negative pattern may predispose delayed afterdepolarizations under β-adrenergic stimulation

Authors

SYNKOVÁ, Iva (203 Czech Republic, belonging to the institution), Markéta BÉBAROVÁ (203 Czech Republic, guarantor, belonging to the institution), Irena ANDRŠOVÁ (203 Czech Republic, belonging to the institution), Larisa CHMELIKOVA (203 Czech Republic), Olga ŠVECOVÁ (203 Czech Republic, belonging to the institution), Jan HOSEK (203 Czech Republic), Michal PÁSEK (203 Czech Republic, belonging to the institution), Pavel VÍT (203 Czech Republic, belonging to the institution), Iveta VALÁŠKOVÁ (203 Czech Republic, belonging to the institution), Renata GAILLYOVÁ (203 Czech Republic, belonging to the institution), Rostislav NAVRATIL (203 Czech Republic) and Tomáš NOVOTNÝ (203 Czech Republic, belonging to the institution)

Edition

Nature Scientific Reports, London, NATURE RESEARCH, 2021, 2045-2322

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

30101 Human genetics

Country of publisher

Germany

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 4.996

RIV identification code

RIV/00216224:14110/21:00120095

Organization unit

Faculty of Medicine

UT WoS

000626725200007

Keywords in English

Long-QT founder variant T309I-Kv7.1; afterdepolarizations; β-adrenergic stimulation

Tags

International impact, Reviewed
Změněno: 16/5/2022 08:52, Mgr. Tereza Miškechová

Abstract

V originále

The variant c.926C > T (p.T309I) in KCNQ1 gene was identified in 10 putatively unrelated Czech families with long QT syndrome (LQTS). Mutation carriers (24 heterozygous individuals) were more symptomatic compared to their non-affected relatives (17 individuals). The carriers showed a mild LQTS phenotype including a longer QTc interval at rest (466 ± 24 ms vs. 418 ± 20 ms) and after exercise (508 ± 32 ms vs. 417 ± 24 ms), 4 syncopes and 2 aborted cardiac arrests. The same haplotype associated with the c.926C > T variant was identified in all probands. Using the whole cell patch clamp technique and confocal microscopy, a complete loss of channel function was revealed in the homozygous setting, caused by an impaired channel trafficking. Dominant negativity with preserved reactivity to β-adrenergic stimulation was apparent in the heterozygous setting. In simulations on a human ventricular cell model, the dysfunction resulted in delayed afterdepolarizations (DADs) and premature action potentials under β-adrenergic stimulation that could be prevented by a slight inhibition of calcium current. We conclude that the KCNQ1 variant c.926C > T is the first identified LQTS-related founder mutation in Central Europe. The dominant negative channel dysfunction may lead to DADs under β-adrenergic stimulation. Inhibition of calcium current could be possible therapeutic strategy in LQTS1 patients refractory to β-blocker therapy.

Links

NV16-30571A, research and development project
Name: Klinický význam a elektrofyziologické zhodnocení mutace c.926C>T genu KCNQ1 (p.T309I) jako možné „founder mutation“ syndromu dlouhého intervalu QT