chr1-40784200-C-CG

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1PM2PP5

The NM_004700.4(KCNQ4):​c.110dupG​(p.Gly38ArgfsTer198) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000136 in 147,406 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000014 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000019 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

KCNQ4
NM_004700.4 frameshift

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 1.66
Variant links:
Genes affected
KCNQ4 (HGNC:6298): (potassium voltage-gated channel subfamily Q member 4) The protein encoded by this gene forms a potassium channel that is thought to play a critical role in the regulation of neuronal excitability, particularly in sensory cells of the cochlea. The current generated by this channel is inhibited by M1 muscarinic acetylcholine receptors and activated by retigabine, a novel anti-convulsant drug. The encoded protein can form a homomultimeric potassium channel or possibly a heteromultimeric channel in association with the protein encoded by the KCNQ3 gene. Defects in this gene are a cause of nonsyndromic sensorineural deafness type 2 (DFNA2), an autosomal dominant form of progressive hearing loss. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-40784200-C-CG is Pathogenic according to our data. Variant chr1-40784200-C-CG is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 3343127.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ4NM_004700.4 linkc.110dupG p.Gly38ArgfsTer198 frameshift_variant Exon 1 of 14 ENST00000347132.10 NP_004691.2 P56696-1B3KQH8
KCNQ4NM_172163.3 linkc.110dupG p.Gly38ArgfsTer198 frameshift_variant Exon 1 of 13 NP_751895.1 P56696-2B3KQH8
KCNQ4XM_047434057.1 linkc.110dupG p.Gly38ArgfsTer198 frameshift_variant Exon 1 of 13 XP_047290013.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ4ENST00000347132.10 linkc.110dupG p.Gly38ArgfsTer198 frameshift_variant Exon 1 of 14 1 NM_004700.4 ENSP00000262916.6 P56696-1
KCNQ4ENST00000509682.6 linkc.110dupG p.Gly38ArgfsTer198 frameshift_variant Exon 1 of 13 5 ENSP00000423756.2 P56696-2

Frequencies

GnomAD3 genomes
AF:
0.0000136
AC:
2
AN:
147406
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000303
Gnomad OTH
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.0000185
AC:
18
AN:
971506
Hom.:
0
Cov.:
24
AF XY:
0.0000151
AC XY:
7
AN XY:
464262
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000199
Gnomad4 OTH exome
AF:
0.0000283
GnomAD4 genome
AF:
0.0000136
AC:
2
AN:
147406
Hom.:
0
Cov.:
32
AF XY:
0.0000139
AC XY:
1
AN XY:
71708
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000303
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:1Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingGeneDxJan 30, 2024Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is not a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpNov 19, 2024This sequence change creates a premature translational stop signal (p.Gly38Argfs*198) in the KCNQ4 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in KCNQ4 are known to be pathogenic (PMID: 23717403). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with KCNQ4-related conditions. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs1168470485; hg19: chr1-41249872; API