rs199956744
Variant summary
Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM5PP2
The NM_000218.3(KCNQ1):c.721G>A(p.Val241Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000267 in 1,612,752 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V241G) 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: Uncertain_significance. The variant received 5 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 152090Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000120 AC: 3AN: 249108 AF XY: 0.0000222 show subpopulations
GnomAD4 exome AF: 0.0000288 AC: 42AN: 1460662Hom.: 0 Cov.: 31 AF XY: 0.0000289 AC XY: 21AN XY: 726660 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000658 AC: 1AN: 152090Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74294 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:3
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Beckwith-Wiedemann syndrome;C1837014:Atrial fibrillation, familial, 3;C1865019:Short QT syndrome type 2;C4551509:Jervell and Lange-Nielsen syndrome 1;C4551647:Long QT syndrome 1 Uncertain:1
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Long QT syndrome Uncertain:1
This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 241 of the KCNQ1 protein (p.Val241Ile). This variant is present in population databases (rs199956744, gnomAD 0.003%). This missense change has been observed in individual(s) with long QT syndrome (PMID: 26669661). ClinVar contains an entry for this variant (Variation ID: 191477). 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. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 30571187). 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. -
Cardiovascular phenotype Uncertain:1
The p.V241I variant (also known as c.721G>A), located in coding exon 5 of the KCNQ1 gene, results from a G to A substitution at nucleotide position 721. The valine at codon 241 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at