rs74772771

Positions:

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS2

The NM_000742.4(CHRNA2):c.140C>T(p.Thr47Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000512 in 1,614,166 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/21 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 0.00035 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00053 ( 1 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:8

Conservation

PhyloP100: 3.10

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 -7 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.102101505).

BP6

Variant 8-27469915-G-A is Benign according to our data. Variant chr8-27469915-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 204979.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Benign=3, Uncertain_significance=2}. Variant chr8-27469915-G-A is described in Lovd as [Likely_benign].

BS2

High AC in GnomAd4 at 53 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHRNA2	NM_000742.4 linkuse as main transcript	c.140C>T	p.Thr47Met	missense_variant	3/7	ENST00000407991.3	NP_000733.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHRNA2	ENST00000407991.3 linkuse as main transcript	c.140C>T	p.Thr47Met	missense_variant	3/7	5	NM_000742.4	ENSP00000385026	P2	Q15822-1

Frequencies

GnomAD3 genomes

AF:

0.000355

AC:

AN:

152210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000262

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.000282

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000603

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000462

AC:

116

AN:

251244

Hom.:

AF XY:

0.000471

AC XY:

AN XY:

135854

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000868

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000139

Gnomad NFE exome

AF:

0.000933

Gnomad OTH exome

AF:

0.000326

GnomAD4 exome

AF:

0.000529

AC:

773

AN:

1461838

Hom.:

Cov.:

AF XY:

0.000484

AC XY:

352

AN XY:

727224

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.000356

Gnomad4 NFE exome

AF:

0.000660

Gnomad4 OTH exome

AF:

0.000215

GnomAD4 genome

AF:

0.000348

AC:

AN:

152328

Hom.:

Cov.:

AF XY:

0.000309

AC XY:

AN XY:

74482

show subpopulations

Gnomad4 AFR

AF:

0.000120

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.000282

Gnomad4 NFE

AF:

0.000603

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000582

Hom.:

Bravo

AF:

0.000329

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.000778

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000349

AC:

ExAC

AF:

0.000494

AC:

EpiCase

AF:

0.000382

EpiControl

AF:

0.000771

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:8

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2Benign:2

Likely benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Dec 13, 2019	This variant is associated with the following publications: (PMID: 21703448, 28488083) -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 04, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	May 01, 2019	- -

Autosomal dominant nocturnal frontal lobe epilepsy 4

Benign:4

Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
Likely benign, criteria provided, single submitter	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	Jul 28, 2017	- -
Benign, criteria provided, single submitter	clinical testing	Mendelics	Aug 22, 2023	- -
Likely benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 21, 2024

- -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 19, 2022

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

0.096

BayesDel_addAF

Benign

-0.18

BayesDel_noAF

Benign

-0.10

CADD

Benign

DANN

Benign

0.94

DEOGEN2

Benign

0.14

T;.;.;.;.;.

Eigen

Benign

-0.51

Eigen_PC

Benign

-0.52

FATHMM_MKL

Uncertain

0.76

LIST_S2

Benign

0.55

T;T;T;T;T;T

M_CAP

Benign

0.041

MetaRNN

Benign

0.10

T;T;T;T;T;T

MetaSVM

Benign

-0.91

MutationAssessor

Benign

0.0

N;.;N;.;.;.

MutationTaster

Benign

1.0

N;N;N

PrimateAI

Benign

0.39

PROVEAN

Benign

0.58

N;.;N;N;N;D

REVEL

Uncertain

0.40

Sift

Uncertain

0.026

D;.;D;D;D;D

Sift4G

Uncertain

0.051

T;D;D;.;D;.

Polyphen

0.83

P;.;.;.;.;.

Vest4

0.56

MVP

0.76

MPC

0.27

ClinPred

0.036

GERP RS

3.3

Varity_R

0.021

gMVP

0.38

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.14

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