Submissions for variant NM_000218.3(KCNQ1):c.1456G>A (p.Ala486Thr)

gnomAD frequency: 0.00004  dbSNP: rs753256800

Total submissions: 8

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Color Diagnostics, LLC DBA Color Health	RCV001841033	SCV001355301	uncertain significance	Cardiac arrhythmia	2023-01-23	criteria provided, single submitter	clinical testing	This missense variant replaces alanine with threonine at codon 486 of the KCNQ1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 9/251412 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.
GeneDx	RCV001751341	SCV001987174	uncertain significance	not provided	2019-10-29	criteria provided, single submitter	clinical testing	In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge
Fulgent Genetics, Fulgent Genetics	RCV002480624	SCV002786326	uncertain significance	Atrial fibrillation, familial, 3; Beckwith-Wiedemann syndrome; Long QT syndrome 1; Jervell and Lange-Nielsen syndrome 1; Short QT syndrome type 2	2021-12-03	criteria provided, single submitter	clinical testing
Labcorp Genetics (formerly Invitae), Labcorp	RCV002560015	SCV003021618	uncertain significance	Long QT syndrome	2024-01-25	criteria provided, single submitter	clinical testing	This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 486 of the KCNQ1 protein (p.Ala486Thr). This variant is present in population databases (rs753256800, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with KCNQ1-related conditions. ClinVar contains an entry for this variant (Variation ID: 925996). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt KCNQ1 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.
Revvity Omics, Revvity	RCV001751341	SCV003811972	uncertain significance	not provided	2021-03-05	criteria provided, single submitter	clinical testing
All of Us Research Program, National Institutes of Health	RCV002560015	SCV004836443	uncertain significance	Long QT syndrome	2023-08-28	criteria provided, single submitter	clinical testing	This missense variant replaces alanine with threonine at codon 486 of the KCNQ1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 9/251412 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.
Ambry Genetics	RCV004619539	SCV005126900	likely benign	Cardiovascular phenotype	2024-05-20	criteria provided, single submitter	clinical testing	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.
PreventionGenetics, part of Exact Sciences	RCV004733172	SCV005357954	uncertain significance	KCNQ1-related disorder	2024-03-26	no assertion criteria provided	clinical testing	The KCNQ1 c.1456G>A variant is predicted to result in the amino acid substitution p.Ala486Thr. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.020% of alleles in individuals of South Asian descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence.