NM_004700.4:c.785A>G

Variant names:

• chr1-40819423-A-G
• rs80358275
• NM_004700.4:c.785A>G

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1 PP3

The NM_004700.4(KCNQ4):​c.785A>G​(p.Asp262Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000547 in 1,461,716 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. D262V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: KCNQ4 NM_004700.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.46
• Publications: 9 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM1: In a hotspot region, there are 2 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, 0.805

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ4	NM_004700.4	c.785A>G	p.Asp262Gly	missense_variant	Exon 5 of 14	ENST00000347132.10	NP_004691.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ4	ENST00000347132.10	c.785A>G	p.Asp262Gly	missense_variant	Exon 5 of 14	1	NM_004700.4	ENSP00000262916.6
KCNQ4	ENST00000509682.6	c.785A>G	p.Asp262Gly	missense_variant	Exon 5 of 13	5		ENSP00000423756.2
KCNQ4	ENST00000443478.3	c.470A>G	p.Asp157Gly	missense_variant	Exon 4 of 13	5		ENSP00000406735.3
KCNQ4	ENST00000506017.1	n.104A>G		non_coding_transcript_exon_variant	Exon 2 of 11	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461716 Hom.: 0 Cov.: 36 AF XY: 0.00000688 AC XY: 5 AN XY: 727172

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

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: 53308

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000719 AC: 8 AN: 1111966

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000370 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Sep 30, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.86	D;D;.
Eigen	Uncertain	0.28
Eigen_PC	Uncertain	0.36
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Benign	0.74	.;T;T
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.80	D;D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Benign	0.21	N;N;N
PhyloP100		4.5
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-2.5	.;N;D
REVEL	Pathogenic	0.87
Sift	Benign	0.28	.;T;T
Sift4G	Benign	0.16	.;T;T
Polyphen		1.0	D;D;B
Vest4		0.30, 0.35
MVP		0.97
MPC		2.6
ClinPred		0.96	D
GERP RS		5.1
Varity_R		0.48
gMVP		0.98
Mutation Taster		=25/75	disease causing

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

Other links and lift over

dbSNP: rs80358275; hg19: chr1-41285095;