rs34320941
Variant summary
Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate
The NM_000218.3(KCNQ1):c.889G>A(p.Gly297Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,613,788 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_000218.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -2 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
KCNQ1 | ENST00000155840.12 | c.889G>A | p.Gly297Ser | missense_variant | Exon 6 of 16 | 1 | NM_000218.3 | ENSP00000155840.2 | ||
KCNQ1 | ENST00000335475.6 | c.508G>A | p.Gly170Ser | missense_variant | Exon 6 of 16 | 1 | ENSP00000334497.5 | |||
KCNQ1 | ENST00000496887.7 | c.628G>A | p.Gly210Ser | missense_variant | Exon 7 of 16 | 5 | ENSP00000434560.2 | |||
KCNQ1 | ENST00000646564.2 | c.478-10481G>A | intron_variant | Intron 2 of 10 | ENSP00000495806.2 |
Frequencies
GnomAD3 genomes AF: 0.0000591 AC: 9AN: 152228Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000200 AC: 5AN: 250094Hom.: 0 AF XY: 0.0000221 AC XY: 3AN XY: 135530
GnomAD4 exome AF: 0.0000103 AC: 15AN: 1461442Hom.: 0 Cov.: 32 AF XY: 0.00000963 AC XY: 7AN XY: 727022
GnomAD4 genome AF: 0.0000591 AC: 9AN: 152346Hom.: 0 Cov.: 33 AF XY: 0.0000537 AC XY: 4AN XY: 74512
ClinVar
Submissions by phenotype
Long QT syndrome Uncertain:2
This missense variant replaces glycine with serine at codon 297 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 been reported in an individual from an apparently healthy control cohort (PMID: 19841300). This variant has been identified in 5/250094 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. -
This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 297 of the KCNQ1 protein (p.Gly297Ser). This variant is present in population databases (rs34320941, gnomAD 0.01%). 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: 67120). 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) indicates that this missense variant is not expected to disrupt KCNQ1 protein function with a negative predictive value of 95%. 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
Reported in at least one African American individual from a cohort of apparently healthy individuals, although follow-up cardiac evaluations or segregation studies were not described (Ackerman et al., 2003; Kapa et al., 2009; Giudicessi et al., 2012); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 19841300, 14661677, 22949429) -
This variant has been reported in the following publications (PMID:14661677;PMID:19841300). -
not specified Uncertain:1
Variant summary: KCNQ1 c.889G>A (p.Gly297Ser) results in a non-conservative amino acid change located in the Ion transport domain (IPR005821) of the encoded protein sequence. Three of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 250094 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.889G>A in individuals affected with Arrhythmia or experimental evidence demonstrating an impact on protein function has been reported. One ClinVar submitter (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Cardiovascular phenotype Uncertain:1
The c.889G>A (p.G297S) alteration is located in exon 6 (coding exon 6) of the KCNQ1 gene. This alteration results from a G to A substitution at nucleotide position 889, causing the glycine (G) at amino acid position 297 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at