8-27469840-C-G

Position:

chr8-27469840-C-G

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4BP6BS2

The NM_000742.4(CHRNA2):c.215G>C(p.Arg72Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000682 in 1,613,994 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R72H) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000066 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:4

Conservation

PhyloP100: 0.668

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 Likely_benign. Variant got -6 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.3068027).

BP6

Variant 8-27469840-C-G is Benign according to our data. Variant chr8-27469840-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 204993.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, Uncertain_significance=1}.

BS2

High AC in GnomAd4 at 14 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHRNA2	NM_000742.4 linkuse as main transcript	c.215G>C	p.Arg72Pro	missense_variant	3/7	ENST00000407991.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNA2	ENST00000407991.3 linkuse as main transcript	c.215G>C	p.Arg72Pro	missense_variant	3/7	5	NM_000742.4	P2	Q15822-1

Frequencies

GnomAD3 genomes

AF:

0.0000920

AC:

AN:

152158

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.000848

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000676

AC:

AN:

251406

Hom.:

AF XY:

0.0000662

AC XY:

AN XY:

135894

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.000397

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000370

Gnomad NFE exome

AF:

0.0000440

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000657

AC:

AN:

1461836

Hom.:

Cov.:

AF XY:

0.0000523

AC XY:

AN XY:

727218

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.000306

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.000187

Gnomad4 NFE exome

AF:

0.0000692

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000920

AC:

AN:

152158

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74334

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.000848

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000868

Hom.:

Bravo

AF:

0.0000529

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000494

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Benign:2

Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jun 01, 2024	CHRNA2: BP4 -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Aug 04, 2020	In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Autosomal dominant nocturnal frontal lobe epilepsy 4

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Jan 01, 2016

This variant was classified as: Uncertain significance. The following ACMG criteria were applied in classifying this variant: PP3,BS1. -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Aug 10, 2023

- -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 04, 2019

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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.28

BayesDel_addAF

Benign

-0.12

BayesDel_noAF

Benign

-0.28

CADD

Pathogenic

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.59

D;.;.;.;.

Eigen

Uncertain

0.34

Eigen_PC

Uncertain

0.39

FATHMM_MKL

Uncertain

0.88

LIST_S2

Uncertain

0.89

D;D;D;D;T

M_CAP

Benign

0.023

MetaRNN

Benign

0.31

T;T;T;T;T

MetaSVM

Benign

-0.55

MutationAssessor

Benign

0.74

N;.;N;.;.

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.60

PROVEAN

Uncertain

-2.7

D;.;D;D;D

REVEL

Uncertain

0.30

Sift

Benign

0.059

T;.;T;T;D

Sift4G

Benign

0.12

T;T;T;.;D

Polyphen

0.99

D;.;.;.;.

Vest4

0.41

MVP

0.79

MPC

0.88

ClinPred

0.57

GERP RS

4.8

Varity_R

0.85

gMVP

0.81

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