NM_000747.3:c.340G>A

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_000747.3(CHRNB1):c.340G>A(p.Val114Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00025 in 1,613,336 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. V114V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00023 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00025 ( 1 hom. )

Consequence

CHRNB1
NM_000747.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 2.63

Publications

5 publications found

Variant links:

Genes affected

CHRNB1 (HGNC:1961): (cholinergic receptor nicotinic beta 1 subunit) The muscle acetylcholine receptor is composed of five subunits: two alpha subunits and one beta, one gamma, and one delta subunit. This gene encodes the beta subunit of the acetylcholine receptor. The acetylcholine receptor changes conformation upon acetylcholine binding leading to the opening of an ion-conducting channel across the plasma membrane. Mutations in this gene are associated with slow-channel congenital myasthenic syndrome. [provided by RefSeq, Jul 2008]

CHRNB1 Gene-Disease associations (from GenCC):

congenital myasthenic syndrome 2C
Inheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
congenital myasthenic syndrome 1A
Inheritance: AD Classification: STRONG Submitted by: PanelApp Australia
congenital myasthenic syndrome 2A
Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
postsynaptic congenital myasthenic syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

CHRNB1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNB1	NM_000747.3 link	c.340G>A	p.Val114Met	missense_variant	Exon 4 of 11	ENST00000306071.7	NP_000738.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNB1	ENST00000306071.7 link	c.340G>A	p.Val114Met	missense_variant	Exon 4 of 11	1	NM_000747.3	ENSP00000304290.2

Frequencies

GnomAD3 genomes

AF:

0.000230

AC:

AN:

152132

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.000471

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000249

AC:

AN:

248858

AF XY:

0.000274

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000580

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000509

Gnomad OTH exome

AF:

0.000494

GnomAD4 exome

AF:

0.000252

AC:

368

AN:

1461204

Hom.:

Cov.:

AF XY:

0.000261

AC XY:

190

AN XY:

726882

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.0000671

AC:

AN:

44712

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26114

East Asian (EAS)

AF:

0.00

AC:

AN:

39686

South Asian (SAS)

AF:

0.0000348

AC:

AN:

86214

European-Finnish (FIN)

AF:

0.0000188

AC:

AN:

53132

Middle Eastern (MID)

AF:

0.000520

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.000309

AC:

344

AN:

1111734

Other (OTH)

AF:

0.000232

AC:

AN:

60370

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.469

Heterozygous variant carriers

100

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

100

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000230

AC:

AN:

152132

Hom.:

Cov.:

AF XY:

0.000175

AC XY:

AN XY:

74320

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41448

American (AMR)

AF:

0.000131

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5180

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10598

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000471

AC:

AN:

68012

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.502

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000412

Hom.:

Bravo

AF:

0.000189

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000465

AC:

ExAC

AF:

0.000264

AC:

EpiCase

AF:

0.000763

EpiControl

AF:

0.00142

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Jul 09, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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 -

Jan 17, 2020

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

CHRNB1: PM2 -

Congenital myasthenic syndrome 2A

Uncertain:1

Nov 21, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 114 of the CHRNB1 protein (p.Val114Met). This variant is present in population databases (rs149433073, gnomAD 0.05%). This variant has not been reported in the literature in individuals affected with CHRNB1-related conditions. ClinVar contains an entry for this variant (Variation ID: 575763). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt CHRNB1 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. -

Inborn genetic diseases

Uncertain:1

Sep 27, 2021

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.340G>A (p.V114M) alteration is located in exon 4 (coding exon 4) of the CHRNB1 gene. This alteration results from a G to A substitution at nucleotide position 340, causing the valine (V) at amino acid position 114 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Congenital myasthenic syndrome 4C

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.50

BayesDel_addAF

Benign

-0.043

BayesDel_noAF

Uncertain

0.050

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.61

D;.;.;.

Eigen

Pathogenic

0.74

Eigen_PC

Uncertain

0.66

FATHMM_MKL

Uncertain

0.96

M_CAP

Benign

0.065

MetaRNN

Uncertain

0.57

D;D;D;D

MetaSVM

Uncertain

0.66

MutationAssessor

Pathogenic

3.6

H;.;.;.

PhyloP100

2.6

PrimateAI

Uncertain

0.69

PROVEAN

Uncertain

-2.5

D;.;D;.

REVEL

Pathogenic

0.70

Sift

Uncertain

0.0020

D;.;D;.

Sift4G

Uncertain

0.0030

D;D;D;D

Polyphen

1.0

D;.;.;.

Vest4

0.69

MVP

0.92

MPC

1.2

ClinPred

0.32

GERP RS

5.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.56

gMVP

0.63

Mutation Taster

=98/2

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over