chr1-40819358-C-A

Position:

• chr1-40819358-C-A

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_004700.4(KCNQ4):​c.720C>A​(p.Thr240=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,570 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: KCNQ4 NM_004700.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.807

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]

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.2).
• BP7: Synonymous conserved (PhyloP=-0.807 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNQ4	NM_004700.4	c.720C>A	p.Thr240=	synonymous_variant	5/14	ENST00000347132.10	NP_004691.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNQ4	ENST00000347132.10	c.720C>A	p.Thr240=	synonymous_variant	5/14	1	NM_004700.4	ENSP00000262916	P2
KCNQ4	ENST00000509682.6	c.720C>A	p.Thr240=	synonymous_variant	5/13	5		ENSP00000423756	A1
KCNQ4	ENST00000443478.3	c.408C>A	p.Thr136=	synonymous_variant	4/13	5		ENSP00000406735
KCNQ4	ENST00000506017.1	n.39C>A		non_coding_transcript_exon_variant	2/11	2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251250 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135862

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000131

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461570 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727098

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: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.20
CADD	Benign	9.9
DANN	Benign	0.80

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

Other links and lift over

dbSNP: rs752131356; hg19: chr1-41285030;