Loss-of-activity-mutation in the cardiac chloride-bicarbonate exchanger AE3 causes short QT syndrome.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29167417.
- Also identified by DOI 10.1038/s41467-017-01630-0 and PMC identifier 5700076.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Patients with short QT syndrome (SQTS) may present with syncope, ventricular fibrillation or sudden cardiac death. Six SQTS susceptibility genes, encoding cation channels, explain <25% of SQTS cases. Here we identify a missense mutation in the anion exchanger (AE3)-encoding SLC4A3 gene in two unrelated families with SQTS. The mutation causes reduced surface expression of AE3 and reduced membrane bicarbonate transport. Slc4a3 knockdown in zebrafish causes increased cardiac pH<sub>i</sub>, short QTc, and reduced systolic duration, which is rescued by wildtype but not mutated SLC4A3. Mechanistic analyses suggest that an increase in pH<sub>i</sub> and decrease in [Cl<sup>-</sup>]<sub>i</sub> shortened the action potential duration. However, other mechanisms may also play a role. Altered anion transport represents a mechanism for development of arrhythmia and may provide new therapeutic possibilities.
Medical subject headings
- Antiporters
- Arrhythmias, Cardiac
- Loss of Function Mutation