rs146751925

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_ModerateBP6_Very_StrongBS2

The NM_000742.4(CHRNA2):c.731A>G(p.Lys244Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000966 in 1,604,526 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 0.00049 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000057 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 8.02

Variant links:

Genes affected

CHRNA2 (HGNC:1956): (cholinergic receptor nicotinic alpha 2 subunit) Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels formed by a pentameric arrangement of alpha and beta subunits to create distinct muscle and neuronal receptors. Neuronal receptors are found throughout the peripheral and central nervous system where they are involved in fast synaptic transmission. This gene encodes an alpha subunit that is widely expressed in the brain. The proposed structure for nAChR subunits is a conserved N-terminal extracellular domain followed by three conserved transmembrane domains, a variable cytoplasmic loop, a fourth conserved transmembrane domain, and a short C-terminal extracellular region. Mutations in this gene cause autosomal dominant nocturnal frontal lobe epilepsy type 4. Single nucleotide polymorphisms (SNPs) in this gene have been associated with nicotine dependence. [provided by RefSeq, Nov 2009]

CHRNA2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -14 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.15419382).

BP6

Variant 8-27463712-T-C is Benign according to our data. Variant chr8-27463712-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 204965.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS2

High AC in GnomAd at 72 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHRNA2	NM_000742.4 linkuse as main transcript	c.731A>G	p.Lys244Arg	missense_variant	6/7	ENST00000407991.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNA2	ENST00000407991.3 linkuse as main transcript	c.731A>G	p.Lys244Arg	missense_variant	6/7	5	NM_000742.4	P2	Q15822-1

Frequencies

GnomAD3 genomes

AF:

0.000493

AC:

AN:

145934

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00171

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000136

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:

0.00152

GnomAD3 exomes

AF:

0.000119

AC:

AN:

251464

Hom.:

AF XY:

0.0000883

AC XY:

AN XY:

135908

show subpopulations

Gnomad AFR exome

AF:

0.00148

Gnomad AMR exome

AF:

0.000173

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000569

AC:

AN:

1458470

Hom.:

Cov.:

AF XY:

0.0000414

AC XY:

AN XY:

725506

show subpopulations

Gnomad4 AFR exome

AF:

0.00203

Gnomad4 AMR exome

AF:

0.000135

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:

0.00000270

Gnomad4 OTH exome

AF:

0.0000829

GnomAD4 genome

AF:

0.000493

AC:

AN:

146056

Hom.:

Cov.:

AF XY:

0.000392

AC XY:

AN XY:

71368

show subpopulations

Gnomad4 AFR

AF:

0.00171

Gnomad4 AMR

AF:

0.000135

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:

0.00151

Alfa

AF:

0.0000824

Hom.:

Bravo

AF:

0.000514

ESP6500AA

AF:

0.00113

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000107

AC:

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:4

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

Invitae

Jan 15, 2024

- -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 13, 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

Benign, criteria provided, single submitter

clinical testing

GeneDx

Jun 25, 2019

- -

CHRNA2-related disorder

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Mar 24, 2023

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Benign

-0.18

BayesDel_noAF

Uncertain

-0.060

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Benign

0.41

T;.;.

Eigen

Benign

0.13

Eigen_PC

Uncertain

0.24

FATHMM_MKL

Uncertain

0.92

LIST_S2

Uncertain

0.92

D;D;D

M_CAP

Benign

0.035

MetaRNN

Benign

0.15

T;T;T

MetaSVM

Benign

-0.55

MutationAssessor

Benign

1.9

L;.;.

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.75

PROVEAN

Benign

-2.1

N;.;N

REVEL

Uncertain

0.49

Sift

Benign

0.23

T;.;T

Sift4G

Benign

0.37

T;T;T

Polyphen

0.33

B;.;.

Vest4

0.77

MVP

0.83

MPC

0.66

ClinPred

0.12

GERP RS

5.0

Varity_R

0.37

gMVP

0.68

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.20

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.20

Position offset: 0

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