1-40819931-G-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_004700.4(KCNQ4):​c.891G>T​(p.Arg297Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,878 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. R297T) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCNQ4
NM_004700.4 missense

Scores

15
3
1

Clinical Significance

Uncertain significance criteria provided, single submitter P:1U:1

Conservation

PhyloP100: 2.75

Publications

6 publications found
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]
KCNQ4 Gene-Disease associations (from GenCC):
  • autosomal dominant nonsyndromic hearing loss 2A
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia
  • nonsyndromic genetic hearing loss
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • autosomal dominant nonsyndromic hearing loss
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • hearing loss disorder
    Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 1 uncertain in NM_004700.4
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.93

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ4NM_004700.4 linkc.891G>T p.Arg297Ser missense_variant Exon 6 of 14 ENST00000347132.10 NP_004691.2 P56696-1B3KQH8

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ4ENST00000347132.10 linkc.891G>T p.Arg297Ser missense_variant Exon 6 of 14 1 NM_004700.4 ENSP00000262916.6 P56696-1
KCNQ4ENST00000509682.6 linkc.891G>T p.Arg297Ser missense_variant Exon 6 of 13 5 ENSP00000423756.2 P56696-2
KCNQ4ENST00000443478.3 linkc.576G>T p.Arg192Ser missense_variant Exon 5 of 13 5 ENSP00000406735.3 H0Y6N7
KCNQ4ENST00000506017.1 linkn.210G>T non_coding_transcript_exon_variant Exon 3 of 11 2

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461878
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727246
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112000
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.225
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Uncertain significance
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Autosomal dominant nonsyndromic hearing loss 2A Pathogenic:1
Aug 20, 2015
ClinVar Staff, National Center for Biotechnology Information (NCBI)
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

not provided Uncertain:1
Oct 16, 2020
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant identified in a mother and son with nonsyndromic hearing loss (Naito et al., 2013); Not observed in large population cohorts (Lek et al., 2016); 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: 23717403) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.55
D
BayesDel_noAF
Pathogenic
0.55
CADD
Pathogenic
30
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.98
D;D;.
Eigen
Pathogenic
0.79
Eigen_PC
Pathogenic
0.69
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Pathogenic
0.99
.;D;D
M_CAP
Uncertain
0.28
D
MetaRNN
Pathogenic
0.93
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.8
H;H;H
PhyloP100
2.8
PrimateAI
Pathogenic
0.82
D
PROVEAN
Pathogenic
-5.6
.;D;D
REVEL
Pathogenic
0.93
Sift
Pathogenic
0.0
.;D;D
Sift4G
Uncertain
0.0020
.;D;D
Polyphen
1.0
D;D;D
Vest4
0.98
MutPred
0.72
Gain of helix (P = 0.132);Gain of helix (P = 0.132);Gain of helix (P = 0.132);
MVP
1.0
MPC
2.4
ClinPred
1.0
D
GERP RS
4.8
Varity_R
0.99
gMVP
0.99
Mutation Taster
=6/94
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs797044971; hg19: chr1-41285603; API