chr11-2572105-G-A
Variant summary
Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1PM5PP3_StrongPP5
The ENST00000155840.12(KCNQ1):c.776G>A(p.Arg259His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,610,292 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R259C) has been classified as Likely pathogenic.
Frequency
Consequence
ENST00000155840.12 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 9 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
KCNQ1 | NM_000218.3 | c.776G>A | p.Arg259His | missense_variant | 5/16 | ENST00000155840.12 | NP_000209.2 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
KCNQ1 | ENST00000155840.12 | c.776G>A | p.Arg259His | missense_variant | 5/16 | 1 | NM_000218.3 | ENSP00000155840 | P1 | |
KCNQ1 | ENST00000335475.6 | c.395G>A | p.Arg132His | missense_variant | 5/16 | 1 | ENSP00000334497 | |||
KCNQ1 | ENST00000496887.7 | c.515G>A | p.Arg172His | missense_variant | 6/16 | 5 | ENSP00000434560 | |||
KCNQ1 | ENST00000646564.2 | c.478-11330G>A | intron_variant | ENSP00000495806 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152188Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000163 AC: 4AN: 244876Hom.: 0 AF XY: 0.0000225 AC XY: 3AN XY: 133458
GnomAD4 exome AF: 0.0000165 AC: 24AN: 1457986Hom.: 0 Cov.: 31 AF XY: 0.0000193 AC XY: 14AN XY: 725428
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152306Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74466
ClinVar
Submissions by phenotype
Long QT syndrome 1 Pathogenic:3
Likely pathogenic, criteria provided, single submitter | clinical testing | Human Genome Sequencing Center Clinical Lab, Baylor College of Medicine | Jan 30, 2018 | This c.776G>A (p.Arg259His) variant in the KCNQ1 gene has been reported in multiple LQTS/SQTS patients with significantly higher prevalence than that observed as extremely low in general population according to gnomad database. Arginine at amino acid position 259 is highly conserved during evolution. Arg259Cys, Arg259Gly and Arg259Leu have been reported in multiple LQTS/SQTS patients as deleterious mutations [PMID: 11021476, 15840476, 19716085, 27868350, 21350584]. Multiple in silico predictions suggest this arginine to histidine change is deleterious. Based upon above evidences, this c.776G>A (p.Arg259His) variant in the KCNQ1 gene is classified as likely pathogenic. - |
Pathogenic, criteria provided, single submitter | clinical testing | Institute of Human Genetics, University of Leipzig Medical Center | Nov 19, 2024 | Criteria applied: PS4,PM1,PM5,PS3_SUP,PP3 - |
Pathogenic, criteria provided, single submitter | clinical testing | Institute of Human Genetics, Clinical Exome/Genome Diagnostics Group, University Hospital Bonn | Oct 11, 2021 | Incidental finding in clinical exome sequencing. PS1, PS3, PP3 - |
not provided Pathogenic:3
Pathogenic, criteria provided, single submitter | clinical testing | CeGaT Center for Human Genetics Tuebingen | Jul 01, 2024 | KCNQ1: PM1, PM5, PS4:Moderate, PM2:Supporting, PP1, PP3, PS3:Supporting - |
Likely pathogenic, criteria provided, single submitter | clinical testing | AiLife Diagnostics, AiLife Diagnostics | Sep 21, 2021 | - - |
Likely pathogenic, criteria provided, single submitter | clinical testing | GeneDx | May 29, 2024 | Identified in individuals with short (SQTS) or long QT syndrome (LQTS) and suspected or witnessed sudden cardiac arrest/death referred for genetic testing at GeneDx and in published literature (PMID: 16922724, 24291113, 26346102, 26370830, 29241489, 34076677, 34389451); Not observed at significant frequency in large population cohorts (gnomAD); Published functional studies suggest that p.(R259H) may have a gain-of-function effect associated with QT interval shortening; however, further studies are needed to clarify the functional impact of this variant and its potential role in SQTS or LQTS (PMID: 26346102); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 28814790, 29759541, 31315195, 19862833, 25974115, 26370830, 30337886, 29021305, 29241489, 26346102, 31447099, 31589614, 34505893, 24291113, 34389451, 16922724, 34076677) - |
Short QT syndrome type 2 Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | Institute of Human Genetics, Clinical Exome/Genome Diagnostics Group, University Hospital Bonn | Oct 11, 2021 | Incidental finding in clinical exome sequencing. PS1, PS3, PP3 - |
Atrial fibrillation, familial, 3;C1865019:Short QT syndrome type 2;C4551509:Jervell and Lange-Nielsen syndrome 1;C4551647:Long QT syndrome 1 Pathogenic:1
Likely pathogenic, criteria provided, single submitter | clinical testing | Juno Genomics, Hangzhou Juno Genomics, Inc | - | PS4_Supporting+PS3+PM2_Supporting+PM5 - |
KCNQ1-related disorder Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | DASA | Jan 05, 2022 | The c.776G>A;p.(Arg259His) missense variant has been observed in affected individual(s) and ClinVar contains an entry for this variant (ClinVar ID 53101; PMID: 16922724; 24291113; 26346102) - PS4. Well-established in vitro or in vivo functional studies support a damaging effect on the gene or gene product (PMID: 26346102) - PS3_supporting. The variant is located in a mutational hot spot and/or critical and well-established functional domain (S4-S5 domain; PMID: 16922724) - PM1. The variant is present at low allele frequencies population databases (rs199472720 – gnomAD 0.0001314%; ABraOM no frequency - http://abraom.ib.usp.br/) - PM2_supporting. Pathogenic missense variant in this residue have been reported (ClinVar 53102; 53100; PMID: 11021476, 21350584, 23158531) - PM5. In summary, the currently available evidence indicates that the variant is pathogenic. - |
Atrial fibrillation, familial, 3;C1865019:Short QT syndrome type 2;C4551647:Long QT syndrome 1 Pathogenic:1
Likely pathogenic, criteria provided, single submitter | clinical testing | Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center | Jun 08, 2021 | PS3, PP3, PM1 - |
Long QT syndrome Pathogenic:1
Pathogenic, criteria provided, single submitter | clinical testing | Labcorp Genetics (formerly Invitae), Labcorp | Nov 24, 2023 | This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 259 of the KCNQ1 protein (p.Arg259His). This variant is present in population databases (rs199472720, gnomAD 0.004%). This missense change has been observed in individuals with long QT syndrome and short QT syndrome (PMID: 16922724, 24291113, 26346102). ClinVar contains an entry for this variant (Variation ID: 53101). 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 expected to disrupt KCNQ1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 26346102). This variant disrupts the p.Arg259 amino acid residue in KCNQ1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 11021476, 21350584, 23158531). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. - |
Cardiovascular phenotype Pathogenic:1
Likely pathogenic, criteria provided, single submitter | clinical testing | Ambry Genetics | May 13, 2022 | The p.R259H variant (also known as c.776G>A), located in coding exon 5 of the KCNQ1 gene, results from a G to A substitution at nucleotide position 776. The arginine at codon 259 is replaced by histidine, an amino acid with highly similar properties. This alteration has been reported in individuals with short QT syndrome (Mazzanti A et al. J Am Coll Cardiol. 2014;63:1300-8; Wu ZJ et al. J Geriatr Cardiol. 2015;12:394-401; Mazzanti A et al. J Am Coll Cardiol. 2017;70(24):3010-3015), in an asymptomatic individual with QTc prolongation and family history of sudden death (Millat G et al. Clin Genet. 2006;70:214-27), and a case with cardiac arrest who was reported to have long QT syndrome (Tiesmeier J et al. Resuscitation. 2021 11;168:176-185). This variant has also been detected in cohorts not selected for the presence of arrhythmia; however, clinical details were limited (Capalbo A et al. PLoS Genet. 2019 10;15(10):e1008409; Zouk H et al. Am J Hum Genet. 2019 09;105(3):588-605). An in vitro assay indicated this variant to impact channel function, resulting in a gain-of-function effect (Wu ZJ et al. J Geriatr Cardiol. 2015;12:394-401). Internal structural analysis indicates this alteration lies in the S4-S5 linking region and may impact modulation of channel gating (Eckey K et al. J Biol Chem. 2014;289(33):22749-58). In addition, other alterations affecting this amino acid (p.R259C (c.775C>T) p.R259L (c.776G>T), and p.R259G (c.775C>G)) have also been reported in association with LQTS (Kapa S et al. Circulation. 2009;120(18):1752-60; Coto E et al. Am J Med Genet A. 2017;173(3):749-752). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. - |
Cardiac arrhythmia Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Color Diagnostics, LLC DBA Color Health | May 17, 2023 | This missense variant replaces arginine with histidine at codon 259 of the KCNQ1 protein. This variant is found within a highly conserved region of the cytoplasmic linker. Rare nontruncating variants in this region (a.a. 249-261) have been shown to be significantly overrepresented in individuals with long QT syndrome (PMID: 32893267). A functional study has shown that this variant alters the channel electrophysiological properties by significantly decreasing current density and peak current (PMID: 34798354), which are inconsistent with the findings from another study (PMID: 26346102). This variant has been reported in several individuals affected with or suspected of having long QT syndrome (PMID: 16922724, 34798354, ClinVar SCV000234416.14), in two individuals affected with short QT syndrome (PMID: 24291113, 26346102), in one individual suspected of having epilepsy (PMID: 31696929), and in an individual with need for cardiopulmonary resuscitation attempts (PMID: 34389451). Different missense substitutions at this codon (p.Arg259Cys, p.Arg259Leu) are known to be pathogenic (ClinVar variation ID 53100, 53102), indicating that arginine at this position is important for KCNQ1 protein function. This variant has been identified in 5/271834 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Although there is a suspicion for a pathogenic role, 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. - |
Congenital long QT syndrome Other:1
not provided, no classification provided | literature only | Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust | - | This variant has been reported as associated with Long QT syndrome in the following publications (PMID:16922724). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at