rs199473475
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP3_Moderate
The NM_000218.3(KCNQ1):c.1321C>T(p.Pro441Ser) variant causes a missense change. The variant allele was found at a frequency of 0.0000279 in 1,613,336 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 (★★).
Frequency
Consequence
NM_000218.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
KCNQ1 | ENST00000155840.12 | c.1321C>T | p.Pro441Ser | missense_variant | Exon 10 of 16 | 1 | NM_000218.3 | ENSP00000155840.2 | ||
KCNQ1 | ENST00000335475.6 | c.940C>T | p.Pro314Ser | missense_variant | Exon 10 of 16 | 1 | ENSP00000334497.5 | |||
KCNQ1 | ENST00000496887.7 | c.964C>T | p.Pro322Ser | missense_variant | Exon 10 of 16 | 5 | ENSP00000434560.2 | |||
KCNQ1 | ENST00000646564.2 | c.781C>T | p.Pro261Ser | missense_variant | Exon 5 of 11 | ENSP00000495806.2 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 151924Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000239 AC: 6AN: 250688Hom.: 0 AF XY: 0.0000221 AC XY: 3AN XY: 135604
GnomAD4 exome AF: 0.0000287 AC: 42AN: 1461412Hom.: 0 Cov.: 32 AF XY: 0.0000289 AC XY: 21AN XY: 727016
GnomAD4 genome AF: 0.0000197 AC: 3AN: 151924Hom.: 0 Cov.: 33 AF XY: 0.0000404 AC XY: 3AN XY: 74184
ClinVar
Submissions by phenotype
not provided Uncertain:1Other:1
A variant of uncertain significance has been identified in the KCNQ1 gene. The P441S variant has not been published as pathogenic; however, it has been reported in a control population (Ackerman et al., 2003). Additionally, this variant is observed in 7/276650 (0.0025%) alleles from individuals of multiple ethnic backgrounds in large population cohorts (Lek et al., 2016). Nonetheless, the P441S variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. In-silico analyses, including protein predictors and evolutionary conservation, support a deleterious effect. Therefore, based on the currently available information, it is unclear whether this variant is pathogenic or rare benign. -
This variant has been reported in the following publications (PMID:14661677;PMID:19841300). -
not specified Uncertain:1
Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. KCNQ1 p.Pro441Ser We classify this as a variant of unknown significance (VUS). This variant has not been reported as a disease-causing mutation. It has been previously reported as a likely benign rare variant by Michael Ackerman’s group after being found in 1/92 (1.1%) of Hispanic control individuals (Ackerman et al. 2003…Kapa later expanded the denominator to 155). Based on this data, it is listed as a polymorphism in the IRCCS Fondazione Salvatore Maugeri inherited arrhythmias database (http://www.fsm.it/cardmoc/). This is a non-conservative amino acid change, resulting in the replacement of a proline (nonpolar) with a serine (polar). Proline at this location is conserved across species according to the GeneDx report. Variants in nearby residues (D446E, P448R, P448L, R451Q, R451W) have been reported in HGMD in association with LQTS, supporting the functional importance of this region of the protein. In silico analysis with PolyPhen-2 (http://genetics.bwh.harvard.edu/pph2/) predicts the variant to be “Probably Damaging” with a score of 0.985. The SIFT score is 0.04 (“Deleterious”) according to the 1000 Genomes database. No variation at this residue is listed as being associated with disease in the cardiodb.org database, which looks across paralog genes. Also, the residue is not conserved across paralogs (http://cardiodb.org/Paralogue_Annotation/gene.php?name=KCNQ1). However, residue 441 is in the cytoplasmic domain of the protein, in which missense variants are 22x more frequent in LQTS cases than in controls (Kapa et al. 2009). In total the variant has been seen in at least 2 out of 7800 individuals from published controls and publicly available population datasets. As mentioned above, this variant was found by Ackerman’s group in one Hispanic individual among >1300 controls of mixed ethnicity: White, Black, Asian, Hispanic, and Unknown/other (Ackerman et al. 2003; Kapa et al. 2009). It is also present in 1 Caucasian individual in the NHLBI Exome Sequencing Project dataset (http://evs.gs.washington.edu/EVS/), which currently includes variant calls on ~4300 Caucasian and ~2200 African American individuals (as of February 18, 2014). There is no variation at this residue listed in 1000 genomes. -
Long QT syndrome Uncertain:1
This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 441 of the KCNQ1 protein (p.Pro441Ser). This variant is present in population databases (rs199473475, gnomAD 0.006%). 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: 67024). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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 c.1321C>T (p.P441S) alteration is located in exon 10 (coding exon 10) of the KCNQ1 gene. This alteration results from a C to T substitution at nucleotide position 1321, causing the proline (P) at amino acid position 441 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Cardiac arrhythmia Uncertain:1
This missense variant replaces proline with serine at codon 441 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). A functional study has shown that this variant results in reduced channel peak current density when expressed in Chinese hamster ovary cells (PMID: 34930020). This variant has been reported in an individual noted with atrial fibrillation in a population screening study, who had no previous indication for cardiac genetic screening (PMID: 34930020).This variant has been identified in 7/282048 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at