20-63346797-C-T

Position:

chr20-63346797-C-T

Variant summary

Our verdict is Benign. Variant got -17 ACMG points: 0P and 17B. BP4BP6_Very_StrongBS1BS2

The NM_000744.7(CHRNA4):c.1825G>A(p.Val609Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000682 in 1,612,624 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000064 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: 7.71

Variant links:

Genes affected

CHRNA4 (HGNC:1958): (cholinergic receptor nicotinic alpha 4 subunit) This gene encodes a nicotinic acetylcholine receptor, which belongs to a superfamily of ligand-gated ion channels that play a role in fast signal transmission at synapses. These pentameric receptors can bind acetylcholine, which causes an extensive change in conformation that leads to the opening of an ion-conducting channel across the plasma membrane. This protein is an integral membrane receptor subunit that can interact with either nAChR beta-2 or nAChR beta-4 to form a functional receptor. Mutations in this gene cause nocturnal frontal lobe epilepsy type 1. Polymorphisms in this gene that provide protection against nicotine addiction have been described. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2012]

CHRNA4 links:

CHRNA4 (HGNC:):

CHRNA4 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -17 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.41592833).

BP6

Variant 20-63346797-C-T is Benign according to our data. Variant chr20-63346797-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 205040.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population mid. gnomad4_exome allele frequency = 0.0000637 (93/1460304) while in subpopulation MID AF= 0.000347 (2/5764). AF 95% confidence interval is 0.000172. There are 0 homozygotes in gnomad4_exome. There are 39 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High AC in GnomAd4 at 17 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHRNA4	NM_000744.7 linkuse as main transcript	c.1825G>A	p.Val609Ile	missense_variant	6/6	ENST00000370263.9	NP_000735.1	P43681-1B4DK78Q59FV0
CHRNA4	NM_001256573.2 linkuse as main transcript	c.1297G>A	p.Val433Ile	missense_variant	6/6		NP_001243502.1	P43681Q4VAQ3B4DK78Q59FV0
CHRNA4	NR_046317.2 linkuse as main transcript	n.2034G>A		non_coding_transcript_exon_variant	6/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHRNA4	ENST00000370263.9 linkuse as main transcript	c.1825G>A	p.Val609Ile	missense_variant	6/6	1	NM_000744.7	ENSP00000359285.4		P43681-1

Frequencies

GnomAD3 genomes

AF:

0.000105

AC:

AN:

152202

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.000188

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.000955

GnomAD3 exomes

AF:

0.0000889

AC:

AN:

247526

Hom.:

AF XY:

0.0000744

AC XY:

AN XY:

134462

show subpopulations

Gnomad AFR exome

AF:

0.0000620

Gnomad AMR exome

AF:

0.000231

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000279

Gnomad NFE exome

AF:

0.0000544

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000637

AC:

AN:

1460304

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

726492

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000291

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.000115

Gnomad4 NFE exome

AF:

0.0000558

Gnomad4 OTH exome

AF:

0.000166

GnomAD4 genome

AF:

0.000112

AC:

AN:

152320

Hom.:

Cov.:

AF XY:

0.000107

AC XY:

AN XY:

74472

show subpopulations

Gnomad4 AFR

AF:

0.0000722

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.000188

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.000945

Alfa

AF:

0.0000559

Hom.:

Bravo

AF:

0.000147

ExAC

AF:

0.0000494

AC:

ClinVar

Significance: Likely benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 15, 2024

- -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 31, 2023

This alteration is classified as likely 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. -

not provided

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Apr 08, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

0.0038

BayesDel_noAF

Uncertain

0.060

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.37

T;.

Eigen

Uncertain

0.57

Eigen_PC

Uncertain

0.51

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

D;D

M_CAP

Pathogenic

0.46

MetaRNN

Benign

0.42

T;T

MetaSVM

Uncertain

0.67

MutationAssessor

Uncertain

2.4

M;.

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-0.69

N;.

REVEL

Pathogenic

0.65

Sift

Uncertain

0.022

D;.

Sift4G

Uncertain

0.028

D;D

Polyphen

1.0

D;.

Vest4

0.49

MutPred

0.60

Loss of catalytic residue at V609 (P = 0.1282);.;

MVP

0.89

MPC

0.81

ClinPred

0.21

GERP RS

4.4

Varity_R

0.11

gMVP

0.75

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

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over