1-40819882-T-C

Variant names:

• chr1-40819882-T-C
• rs80358278
• NM_004700.4:c.842T>C

Variant summary

Our verdict is Pathogenic. The variant received 20 ACMG points: 20P and 0B. PS3 PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_004700.4(KCNQ4):​c.842T>C​(p.Leu281Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,268 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV001791714: Published functional studies demonstrate the L281S mutation leads to non-functional channels and improper trafficking of mutant channels to the cell surface with a dominant negative effect on WT channels (Kim et al., 2011" and additional evidence is available in ClinVar. Synonymous variant affecting the same amino acid position (i.e. L281L) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNQ4 NM_004700.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 8.02
• Publications: 23 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
• 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: Pathogenic. The variant received 20 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV001791714: Published functional studies demonstrate the L281S mutation leads to non-functional channels and improper trafficking of mutant channels to the cell surface with a dominant negative effect on WT channels (Kim et al., 2011; Gao et al., 2013); SCV003523271: Experimental studies have shown that this missense change affects KCNQ4 function (PMID: 23750663).
• PM1: In a hotspot region, there are 14 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_004700.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984
• PP5: Variant 1-40819882-T-C is Pathogenic according to our data. Variant chr1-40819882-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 6246.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004700.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ4	NM_004700.4	MANE Select	c.842T>C	p.Leu281Ser	missense	Exon 6 of 14	NP_004691.2
	KCNQ4	NM_172163.3		c.842T>C	p.Leu281Ser	missense	Exon 6 of 13	NP_751895.1	P56696-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ4	ENST00000347132.10	TSL:1 MANE Select	c.842T>C	p.Leu281Ser	missense	Exon 6 of 14	ENSP00000262916.6	P56696-1
	KCNQ4	ENST00000967337.1		c.842T>C	p.Leu281Ser	missense	Exon 6 of 14	ENSP00000637396.1
	KCNQ4	ENST00000967338.1		c.842T>C	p.Leu281Ser	missense	Exon 6 of 14	ENSP00000637397.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461268 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726996

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44722

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86240

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111448

Other (OTH) AF: 0.00 AC: 0 AN: 60372

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
4	-	-	Autosomal dominant nonsyndromic hearing loss 2A (4)
2	-	-	not provided (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.93	D
M_CAP	Pathogenic	0.44	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		8.0
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-5.6	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.91		Gain of glycosylation at L281 (P = 0.0078)
MVP		0.99
MPC		2.6
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.91
gMVP		0.99
Mutation Taster		=3/97	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

Other links and lift over

dbSNP: rs80358278; hg19: chr1-41285554;