rs199473449
Variant summary
Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM5PP2PP3_Strong
The NM_000218.3(KCNQ1):c.397G>A(p.Val133Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,930 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V133A) has been classified as Uncertain significance.
Frequency
Consequence
NM_000218.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 9 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152180Hom.: 0 Cov.: 34 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251392 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000684 AC: 10AN: 1461750Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3AN XY: 727180 show subpopulations
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152180Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0AN XY: 74324 show subpopulations
ClinVar
Submissions by phenotype
Long QT syndrome Uncertain:2
This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 133 of the KCNQ1 protein (p.Val133Ile). This variant is present in population databases (rs199473449, gnomAD 0.0009%). This missense change has been observed in individual(s) with long QT syndrome (PMID: 12877697). ClinVar contains an entry for this variant (Variation ID: 67069). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. Experimental studies have shown that this missense change does not substantially affect KCNQ1 function (PMID: 27810088, 29532034, 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. -
This missense variant replaces valine with isoleucine at codon 133 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). Functional studies have shown that this variant has no substantial impact on channel function in intro (PMID: 27810088, 29532034, 30571187, 31518351). This variant has been reported in a few individuals affected with long QT syndrome or other cardiovascular disease (PMID: 15840476, 19716085, 31696929), and in multiple individuals from a family, none of whom had indications of long QT syndrome (PMID: 27810088). This variant has been identified in 1/251392 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. -
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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Cardiac arrhythmia Uncertain:1
This missense variant replaces valine with isoleucine at codon 133 of the KCNQ1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function. Functional studies have shown that this variant has no substantial impact on channel function in intro (PMID: 27810088, 29532034, 30571187, 31518351). This variant has been reported in a few individuals affected with long QT syndrome or other cardiovascular disease (PMID: 15840476, 19716085, 31696929). This variant has also been observed in multiple individuals from a family, who were all unaffected with long QT syndrome (PMID: 27810088). This variant has been identified in 1/251392 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. -
Congenital long QT syndrome Other:1
This variant has been reported as associated with Long QT syndrome in the following publications (PMID:12877697;PMID:15840476;PMID:19716085). 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