LQTS-associated mutation A257G in α1-syntrophin interacts with the intragenic variant P74L to modify its biophysical phenotype.

Cheng, Jianding; Van Norstrand, David W.; Medeiros Domingo, Argelia; Tester, David J.; Valdivia, Carmen R.; Tan, Bi-Hua; Vatta, Matteo; Makielski, Jonathan C.; Ackerman, Michael J. (2011). LQTS-associated mutation A257G in α1-syntrophin interacts with the intragenic variant P74L to modify its biophysical phenotype. Cardiogenetics, 1(1) PAGEPress

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The SNTA1-encoded α1-syntrophin (SNTA1) missense mutation, p.A257G, causes long QT syndrome (LQTS) by pathogenic accentuation of Nav1.5's sodium current (I Na). Subsequently, we found p.A257G in combination with the SNTA1 polymorphism, p.P74L in 4 victims of sudden infant death syndrome (SIDS) as well as in 3 adult controls. We hypothesized that p.P74L-SNTA1 could functionally modify the pathogenic phenotype of p.A257G-SNTA1, thus explaining its occurrence in non-LQTS populations. The SNTA1 variants p.P74L, p.A257G, and the combination variant p.P74L/p.A257G were engineered using PCR-based overlap-extension and were co-expressed heterologously with SCN5A in HEK293 cells. I Na was recorded using the whole-cell method. Compared to wild-type (WT), the significant increase in peak I Na and window current found with p.A257G was reversed by the intragenic variant p.P74L (p.P74L/p.A257G). These results report for the first time the intragenic rescue of an LQT-associated SNTA1 mutation when found in combination with the SNTA1 polymorphism p.P74L, suggesting an ever-increasing picture of complexity in terms of genetic risk stratification for arrhythmia.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Department of Cardiovascular Disorders (DHGE) > Clinic of Cardiology

UniBE Contributor:

Medeiros Domingo, Argelia

Subjects:

600 Technology > 610 Medicine & health

ISSN:

2035-8253

Publisher:

PAGEPress

Language:

English

Submitter:

Argelia Medeiros Domingo

Date Deposited:

20 Jun 2014 11:58

Last Modified:

05 Dec 2014 06:54

PubMed ID:

24319568

Uncontrolled Keywords:

SCN5A, genetics, ion channels, long-QT syndrome, syntrophin

BORIS DOI:

10.7892/boris.42270

URI:

https://boris.unibe.ch/id/eprint/42270

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