rs956666801
Variant summary
Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2_SupportingPP3PM5PM1
This summary comes from the ClinGen Evidence Repository: The c.825G>C variant in KCNQ4 is a missense variant predicted to cause substitution of tryptophan by cysteine at amino acid 275 (p.Trp275Cys). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). The computational predictor REVEL gives a score of 0.928, which is above the threshold of 0.7, evidence that correlates with impact to KCNQ4 function (PP3). This variant has been reported in one individual with hearing loss and segregated in an affected first degree relative (SCV000712456.1). This variant is located within the pore-forming intramembrane region (amino acids 271-292) where many variants that cause autosomal dominant hearing loss are located and is defined as a critical functional domain by the ClinGen Hearing Loss VCEP (PM1; PMID:23717403). A different missense variant at the same codon (p.Trp275Arg) has been classified as Pathogenic by the ClinGen Hearing Loss VCEP (PM5; ClinVar Variation ID 204597, PMID:25116015). In summary, this variant is classified as Likely Pathogenic for autosomal dominant sensorineural hearing loss based on the ACMG/AMP criteria applied, as specified by the ClinGen Hearing Loss VCEP: PM2_Supporting, PP3, PM1, PM5. (VCEP specifications version 2; 10.18.2023). LINK:https://erepo.genome.network/evrepo/ui/classification/CA21112664/MONDO:0019497/005
Frequency
Consequence
NM_004700.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
KCNQ4 | ENST00000347132.10 | c.825G>C | p.Trp275Cys | missense_variant | Exon 5 of 14 | 1 | NM_004700.4 | ENSP00000262916.6 | ||
KCNQ4 | ENST00000509682.6 | c.825G>C | p.Trp275Cys | missense_variant | Exon 5 of 13 | 5 | ENSP00000423756.2 | |||
KCNQ4 | ENST00000443478.3 | c.510G>C | p.Trp170Cys | missense_variant | Exon 4 of 13 | 5 | ENSP00000406735.3 | |||
KCNQ4 | ENST00000506017.1 | n.144G>C | non_coding_transcript_exon_variant | Exon 2 of 11 | 2 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461684Hom.: 0 Cov.: 36 AF XY: 0.00000138 AC XY: 1AN XY: 727170
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
not provided Pathogenic:2
This sequence change replaces tryptophan, which is neutral and slightly polar, with cysteine, which is neutral and slightly polar, at codon 275 of the KCNQ4 protein (p.Trp275Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with KCNQ4-related conditions. ClinVar contains an entry for this variant (Variation ID: 505302). 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 KCNQ4 protein function with a positive predictive value of 95%. This variant disrupts the p.Trp275 amino acid residue in KCNQ4. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 25116015, 31995783). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 30311386, 32746448, 25116015, 23717403) -
Nonsyndromic genetic hearing loss Pathogenic:1
The c.825G>C variant in KCNQ4 is a missense variant predicted to cause substitution of tryptophan by cysteine at amino acid 275 (p.Trp275Cys). This variant is absent from gnomAD v2.1.1 (PM2_Supporting). The computational predictor REVEL gives a score of 0.928, which is above the threshold of 0.7, evidence that correlates with impact to KCNQ4 function (PP3). This variant has been reported in one individual with hearing loss and segregated in an affected first degree relative (SCV000712456.1). This variant is located within the pore-forming intramembrane region (amino acids 271-292) where many variants that cause autosomal dominant hearing loss are located and is defined as a critical functional domain by the ClinGen Hearing Loss VCEP (PM1; PMID: 23717403). A different missense variant at the same codon (p.Trp275Arg) has been classified as Pathogenic by the ClinGen Hearing Loss VCEP (PM5; ClinVar Variation ID 204597, PMID: 25116015). In summary, this variant is classified as Likely Pathogenic for autosomal dominant sensorineural hearing loss based on the ACMG/AMP criteria applied, as specified by the ClinGen Hearing Loss VCEP: PM2_Supporting, PP3, PM1, PM5. (VCEP specifications version 2; 10.18.2023). -
not specified Uncertain:1
Variant classified as Uncertain Significance - Favor Pathogenic. The p.Trp275Cys variant in KCNQ4 has not been previously reported in individuals with hearing l oss and was absent from large population studies. The tryptophan (Trp) at positi on 275 is highly conserved in mammals and evolutionarily distant species, and co mputational prediction tools suggest the p.Trp275Cys may impact the protein. In addition, a different missense variant at the same amino acid position (p.Trp275 Arg) has been previously reported in an individual with hearing loss and segrega ted in 11 affected relatives (Wang 2014). These data suggest that a change at th is position may not be tolerated, however additional data is needed to assume pa thogenicity for this missense variant. In summary, while there is some suspicion for a pathogenic role, the clinical significance of the p.Trp275Cys variant is uncertain. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at