rs199472788
Variant summary
Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PP2PP3_Strong
The NM_000218.3(KCNQ1):c.1556G>A(p.Arg519His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000254 in 1,613,920 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R519C) has been classified as Uncertain significance.
Frequency
Consequence
NM_000218.3 missense
Scores
Clinical Significance
Conservation
Publications
- long QT syndromeInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- long QT syndrome 1Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
- Jervell and Lange-Nielsen syndromeInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- Jervell and Lange-Nielsen syndrome 1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
- atrial fibrillation, familial, 3Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- short QT syndromeInheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet
- short QT syndrome type 2Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
- familial atrial fibrillationInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Jervell and Lange-Nielsen syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hypertrophic cardiomyopathyInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 7 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152110Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 251404 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.0000267 AC: 39AN: 1461810Hom.: 0 Cov.: 31 AF XY: 0.0000275 AC XY: 20AN XY: 727208 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152110Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74296 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Long QT syndrome 1 Uncertain:2
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This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Long QT syndrome Uncertain:2
This missense variant replaces arginine with histidine at codon 519 of the KCNQ1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). This variant is found within a highly conserved region of the c-terminal cytoplasmic domain. Rare nontruncating variants in this region (a.a. 509-575) have been shown to be significantly overrepresented in individuals with long QT syndrome (PMID: 32893267). A functional study has shown that this variant causes a reduction in channel peak current density in transfected cells (PMID: 34930020). This variant has been reported in three unrelated individuals affected with long QT syndrome (PMID: 26118460), as well as in two healthy individuals (PMID: 19841300, 14661677). This variant has been identified in 7/282764 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. -
This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 519 of the KCNQ1 protein (p.Arg519His). This variant is present in population databases (rs199472788, gnomAD 0.006%). This missense change has been observed in individual(s) with long QT syndrome (PMID: 14661677, 19841300, 26118460, 32893267, 34930020). ClinVar contains an entry for this variant (Variation ID: 67038). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on KCNQ1 protein function. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 34930020). 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. -
not provided Uncertain:1Other:1
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This variant has been reported in the following publications (PMID:14661677;PMID:19841300). -
Atrial fibrillation, familial, 3 Uncertain:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Jervell and Lange-Nielsen syndrome 1 Uncertain:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
KCNQ1-related disorder Uncertain:1
The KCNQ1 c.1556G>A variant is predicted to result in the amino acid substitution p.Arg519His. This variant was reported in an individual with long QT syndrome (Itoh et al 2015. PubMed ID: 26118460). This variant is reported in 0.0065% of alleles in individuals of South Asian descent in gnomAD (http://gnomad.broadinstitute.org/variant/11-2790115-G-A). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Cardiovascular phenotype Uncertain:1
The c.1556G>A (p.R519H) alteration is located in exon 12 (coding exon 12) of the KCNQ1 gene. This alteration results from a G to A substitution at nucleotide position 1556, causing the arginine (R) at amino acid position 519 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Cardiac arrhythmia Uncertain:1
This missense variant replaces arginine with histidine at codon 519 of the KCNQ1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). This variant is found within a highly conserved region of the c-terminal cytoplasmic domain. Rare nontruncating variants in this region (a.a. 509-575) have been shown to be significantly overrepresented in individuals with long QT syndrome (PMID: 32893267). A functional study has shown that this variant causes a reduction in channel peak current density in transfected cells (PMID: 34930020). This variant has been reported in three unrelated individuals affected with long QT syndrome (PMID: 26118460), as well as in two healthy individuals (PMID: 19841300, 14661677). This variant has been identified in 7/282764 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. -
Short QT syndrome type 2 Benign:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at