rs763326539

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP3

The NM_004700.4(KCNQ4):​c.832A>G​(p.Thr278Ala) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000062 in 1,613,312 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. T278T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

KCNQ4
NM_004700.4 missense, splice_region

Scores

8
7
4
Splicing: ADA: 0.3557
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.46

Publications

3 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: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a hotspot region, there are 13 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_004700.4
PP3
MetaRNN computational evidence supports a deleterious effect, 0.794

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ4NM_004700.4 linkc.832A>G p.Thr278Ala missense_variant, splice_region_variant Exon 5 of 14 ENST00000347132.10 NP_004691.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ4ENST00000347132.10 linkc.832A>G p.Thr278Ala missense_variant, splice_region_variant Exon 5 of 14 1 NM_004700.4 ENSP00000262916.6
KCNQ4ENST00000509682.6 linkc.832A>G p.Thr278Ala missense_variant, splice_region_variant Exon 5 of 13 5 ENSP00000423756.2
KCNQ4ENST00000443478.3 linkc.517A>G p.Thr173Ala missense_variant, splice_region_variant Exon 4 of 13 5 ENSP00000406735.3
KCNQ4ENST00000506017.1 linkn.151A>G splice_region_variant, non_coding_transcript_exon_variant Exon 2 of 11 2

Frequencies

GnomAD3 genomes
AF:
0.0000264
AC:
4
AN:
151660
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000262
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251390
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000410
AC:
6
AN:
1461652
Hom.:
0
Cov.:
36
AF XY:
0.00000413
AC XY:
3
AN XY:
727158
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000112
AC:
5
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53296
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111926
Other (OTH)
AF:
0.00
AC:
0
AN:
60382
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000264
AC:
4
AN:
151660
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74032
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41220
American (AMR)
AF:
0.000262
AC:
4
AN:
15248
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5150
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4802
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10574
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67888
Other (OTH)
AF:
0.00
AC:
0
AN:
2082
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.000140
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Jul 11, 2017
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Thr278Ala variant in KCNQ4 has not been previously reported in individuals with hearing loss, but has been identified in 1/33578 Latino chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org/; dbSNP r s763326539). Although this variant has been seen in the general population, its frequency is not high enough to rule out a pathogenic role. Computational predic tion tools and conservation analysis do not provide strong support for or agains t an impact to the protein. This variant is located in the last three bases of t he exon, which is part of the 5? splice region. Computational tools do not sugge st an impact to splicing. However, this information is not predictive enough to rule out pathogenicity. In summary, the clinical significance of the p.Thr278Ala variant is uncertain. -

not provided Uncertain:1
Jan 27, 2025
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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; Has not been previously published as pathogenic or benign in association with a KCNQ4-related disorder to our knowledge; This variant is associated with the following publications: (PMID: 31434872, 23717403, 30311386) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.42
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.30
CADD
Pathogenic
33
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.85
D;D;.
Eigen
Uncertain
0.37
Eigen_PC
Uncertain
0.44
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Uncertain
0.92
.;D;D
M_CAP
Pathogenic
0.39
D
MetaRNN
Pathogenic
0.79
D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Benign
0.94
L;L;L
PhyloP100
4.5
PrimateAI
Pathogenic
0.80
D
PROVEAN
Uncertain
-2.8
.;D;D
REVEL
Pathogenic
0.79
Sift
Benign
0.034
.;D;D
Sift4G
Benign
0.39
.;T;T
Polyphen
1.0
D;D;P
Vest4
0.72, 0.69
MutPred
0.51
Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);
MVP
0.94
MPC
2.1
ClinPred
0.96
D
GERP RS
5.1
Varity_R
0.65
gMVP
0.93
Mutation Taster
=14/86
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.36
dbscSNV1_RF
Benign
0.42
SpliceAI score (max)
0.030
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: rs763326539; hg19: chr1-41285142; API