dbSNP rs751425807: KCNQ2:p.Ala822Pro (chr20-63406799-C-G) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2PP2BP4

The NM_172107.4(KCNQ2):c.2464G>C(p.Ala822Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,270 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict 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: 34)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.02

Variant links:

Genes affected

KCNQ2 (HGNC:6296): (potassium voltage-gated channel subfamily Q member 2) The M channel is a slowly activating and deactivating potassium channel that plays a critical role in the regulation of neuronal excitability. The M channel is formed by the association of the protein encoded by this gene and a related protein encoded by the KCNQ3 gene, both integral membrane proteins. M channel currents are inhibited by M1 muscarinic acetylcholine receptors and activated by retigabine, a novel anti-convulsant drug. Defects in this gene are a cause of benign familial neonatal convulsions type 1 (BFNC), also known as epilepsy, benign neonatal type 1 (EBN1). At least five transcript variants encoding five different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

KCNQ2 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant in the KCNQ2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 319 curated pathogenic missense variants (we use a threshold of 10). The gene has 78 curated benign missense variants. Gene score misZ: 4.0411 (above the threshold of 3.09). Trascript score misZ: 3.6968 (above the threshold of 3.09). GenCC associations: The gene is linked to seizures, benign familial neonatal, 1, neonatal-onset developmental and epileptic encephalopathy, benign familial neonatal-infantile seizures, benign neonatal seizures, malignant migrating partial seizures of infancy, neonatal encephalopathy with non-epileptic myoclonus, complex neurodevelopmental disorder, seizures, benign familial neonatal, 2, developmental and epileptic encephalopathy, 7, benign familial infantile epilepsy.

BP4

Computational evidence support a benign effect (MetaRNN=0.29254705).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ2	NM_172107.4 link	c.2464G>C	p.Ala822Pro	missense_variant	Exon 17 of 17	ENST00000359125.7	NP_742105.1	O43526-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ2	ENST00000359125.7 link	c.2464G>C	p.Ala822Pro	missense_variant	Exon 17 of 17	1	NM_172107.4	ENSP00000352035.2		O43526-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000402

AC:

AN:

248722

Hom.:

AF XY:

0.00000740

AC XY:

AN XY:

135140

show subpopulations

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:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1460270

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726428

show subpopulations

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:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000826

AC:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.10

BayesDel_noAF

Benign

-0.28

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.020

.;T;T;T;.;.

Eigen

Benign

0.064

Eigen_PC

Benign

0.012

FATHMM_MKL

Benign

0.45

LIST_S2

Uncertain

0.88

D;D;D;D;D;D

M_CAP

Uncertain

0.091

MetaRNN

Benign

0.29

T;T;T;T;T;T

MetaSVM

Benign

-0.59

MutationAssessor

Benign

1.4

.;.;L;.;.;.

PrimateAI

Uncertain

0.57

PROVEAN

Benign

-0.82

.;.;N;.;N;.

REVEL

Benign

0.21

Sift

Uncertain

0.012

.;.;D;.;D;.

Sift4G

Uncertain

0.026

D;.;D;D;D;D

Polyphen

0.99

D;.;D;.;D;D

Vest4

0.37

MutPred

0.38

.;.;Gain of relative solvent accessibility (P = 0.0023);.;.;.;

MVP

0.54

MPC

1.8

ClinPred

0.71

GERP RS

4.0

Varity_R

0.32

gMVP

0.29

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Computational scores

Splicing

Publications

LitVar

Other links and lift over