rs779199533

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_000748.3(CHRNB2):c.317G>A(p.Arg106Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000093 in 1,612,434 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R106W) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

CHRNB2
NM_000748.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 10.0

Variant links:

Genes affected

CHRNB2 (HGNC:1962): (cholinergic receptor nicotinic beta 2 subunit) Neuronal acetylcholine receptors are homo- or heteropentameric complexes composed of homologous alpha and beta subunits. They belong to a superfamily of ligand-gated ion channels which allow the flow of sodium and potassium across the plasma membrane in response to ligands such as acetylcholine and nicotine. This gene encodes one of several beta subunits. Mutations in this gene are associated with autosomal dominant nocturnal frontal lobe epilepsy. [provided by RefSeq, Jul 2008]

CHRNB2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.898

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
CHRNB2	NM_000748.3 linkuse as main transcript	c.317G>A	p.Arg106Gln	missense_variant	4/6	ENST00000368476.4
CHRNB2	XM_017000180.3 linkuse as main transcript	c.-58G>A		5_prime_UTR_variant	1/3
CHRNB2	XR_001736952.3 linkuse as main transcript	n.584G>A		non_coding_transcript_exon_variant	4/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
CHRNB2	ENST00000368476.4 linkuse as main transcript	c.317G>A	p.Arg106Gln	missense_variant	4/6	1	NM_000748.3	P4
CHRNB2	ENST00000637900.1 linkuse as main transcript	c.323G>A	p.Arg108Gln	missense_variant	4/6	5		A1
CHRNB2	ENST00000636034.1 linkuse as main transcript	c.317G>A	p.Arg106Gln	missense_variant, NMD_transcript_variant	4/9	5
CHRNB2	ENST00000636695.1 linkuse as main transcript			downstream_gene_variant		5

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152026

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:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000121

AC:

AN:

248876

Hom.:

AF XY:

0.0000223

AC XY:

AN XY:

134382

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000177

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000959

AC:

AN:

1460408

Hom.:

Cov.:

AF XY:

0.00000826

AC XY:

AN XY:

726336

show subpopulations

Gnomad4 AFR exome

AF:

0.000120

Gnomad4 AMR exome

AF:

0.00

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:

0.00000900

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152026

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74240

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:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000434

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 17, 2023

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 106 of the CHRNB2 protein (p.Arg106Gln). This variant is present in population databases (rs779199533, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with CHRNB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 205065). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt CHRNB2 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Autosomal dominant nocturnal frontal lobe epilepsy 3

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genomic Research Center, Shahid Beheshti University of Medical Sciences

Aug 07, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.94

BayesDel_addAF

Pathogenic

0.17

BayesDel_noAF

Pathogenic

0.17

Cadd

Pathogenic

Dann

Pathogenic

1.0

DEOGEN2

Pathogenic

0.84

D;.

Eigen

Pathogenic

0.82

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.97

D;D

M_CAP

Benign

0.033

MetaRNN

Pathogenic

0.90

D;D

MetaSVM

Uncertain

0.22

MutationAssessor

Uncertain

2.2

M;.

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.63

PROVEAN

Uncertain

-3.5

D;.

REVEL

Pathogenic

0.82

Sift

Benign

0.048

D;.

Sift4G

Uncertain

0.042

D;.

Polyphen

0.99

D;.

Vest4

0.76

MutPred

0.73

Gain of catalytic residue at R106 (P = 0.0111);.;

MVP

0.95

MPC

2.2

ClinPred

0.99

GERP RS

5.0

Varity_R

0.61

gMVP

0.67

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