rs748120886

Positions:

chr20-63419650-G-A

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 1P and 13B. PP2BP4_StrongBP6BS1BS2

The NM_172107.4(KCNQ2):c.1270C>T(p.Pro424Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,611,498 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)

Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

KCNQ2
NM_172107.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:2

Conservation

PhyloP100: 0.650

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:

KCNQ2 (HGNC:):

KCNQ2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -12 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KCNQ2. . Gene score misZ 4.0411 (greater than the threshold 3.09). Trascript score misZ 3.6968 (greater than threshold 3.09). GenCC has associacion of gene with 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=0.05456379).

BP6

Variant 20-63419650-G-A is Benign according to our data. Variant chr20-63419650-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 405210.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1, Benign=1}.

BS1

Variant frequency is greater than expected in population amr. gnomad4_exome allele frequency = 0.0000164 (24/1459266) while in subpopulation AMR AF= 0.000517 (23/44520). AF 95% confidence interval is 0.000352. There are 0 homozygotes in gnomad4_exome. There are 13 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High AC in GnomAdExome4 at 24 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNQ2	NM_172107.4 linkuse as main transcript	c.1270C>T	p.Pro424Ser	missense_variant	12/17	ENST00000359125.7	NP_742105.1	O43526-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNQ2	ENST00000359125.7 linkuse as main transcript	c.1270C>T	p.Pro424Ser	missense_variant	12/17	1	NM_172107.4	ENSP00000352035.2		O43526-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152232

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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

GnomAD3 exomes

AF:

0.0000898

AC:

AN:

245050

Hom.:

AF XY:

0.000105

AC XY:

AN XY:

132864

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000615

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000904

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000164

AC:

AN:

1459266

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

725754

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000517

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152232

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74374

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000529

ExAC

AF:

0.0000578

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jul 28, 2017

A variant of uncertain significance has been identified in the KCNQ2 gene. The P424S variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The P424S variant is observed in 6/7862 (0.1%) alleles from individuals of Latino background (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). This substitution occurs at a position that is not conserved. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. However, the P424S variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. Additionally, the majority of missense variants in this gene are considered pathogenic (Stenson et al., 2014). Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Inborn genetic diseases

Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

May 25, 2017

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Early infantile epileptic encephalopathy with suppression bursts

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 14, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.054

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Benign

-0.11

CADD

Benign

9.3

DANN

Benign

0.84

DEOGEN2

Benign

0.19

Eigen

Benign

-0.80

Eigen_PC

Benign

-0.62

FATHMM_MKL

Benign

0.32

LIST_S2

Benign

0.51

M_CAP

Benign

0.047

MetaRNN

Benign

0.055

MetaSVM

Uncertain

0.031

MutationAssessor

Benign

0.46

PrimateAI

Benign

0.32

PROVEAN

Benign

0.15

REVEL

Benign

0.28

Sift

Benign

0.45

Sift4G

Benign

0.61

Polyphen

0.0

Vest4

0.26

MutPred

0.20

Gain of phosphorylation at P424 (P = 0.0126);

MVP

0.37

MPC

0.63

ClinPred

0.040

GERP RS

1.0

Varity_R

0.027

gMVP

0.27

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over