17-7454479-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PP3_Strong

The NM_000747.3(CHRNB1):c.1003C>T(p.Arg335Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000805 in 1,613,980 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. R335H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 30)

Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

CHRNB1
NM_000747.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.11

Publications

0 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:

ENSG00000308645 (HGNC:):

ENSG00000308645 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.983

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNB1	NM_000747.3 link	c.1003C>T	p.Arg335Cys	missense_variant	Exon 8 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.1003C>T	p.Arg335Cys	missense_variant	Exon 8 of 11	1	NM_000747.3	ENSP00000304290.2

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152090

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

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

GnomAD2 exomes

AF:

0.0000278

AC:

AN:

251484

AF XY:

0.0000221

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000202

Gnomad ASJ exome

AF:

0.00

Gnomad EAS 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:

0.00000752

AC:

AN:

1461890

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727244

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.000179

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1112010

Other (OTH)

AF:

0.0000166

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.466

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome 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

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152090

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74284

show subpopulations

African (AFR)

AF:

0.0000242

AC:

AN:

41406

American (AMR)

AF:

0.00

AC:

AN:

15258

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5182

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10602

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68028

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

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:

0.00

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Congenital myasthenic syndrome 2A

Uncertain:1

Aug 01, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 335 of the CHRNB1 protein (p.Arg335Cys). This variant is present in population databases (rs779467380, gnomAD 0.02%). 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: 476148). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on CHRNB1 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.78

BayesDel_addAF

Pathogenic

0.18

BayesDel_noAF

Pathogenic

0.30

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.84

D;.;.

Eigen

Pathogenic

0.80

Eigen_PC

Pathogenic

0.73

FATHMM_MKL

Pathogenic

0.99

M_CAP

Uncertain

0.21

MetaRNN

Pathogenic

0.98

D;D;D

MetaSVM

Pathogenic

0.89

MutationAssessor

Pathogenic

3.0

M;.;.

PhyloP100

6.1

PrimateAI

Uncertain

0.78

PROVEAN

Pathogenic

-7.3

D;D;.

REVEL

Pathogenic

0.88

Sift

Pathogenic

0.0

D;D;.

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

D;.;.

Vest4

0.87

MutPred

0.94

Loss of disorder (P = 0.0082);.;.;

MVP

0.97

MPC

1.4

ClinPred

0.99

GERP RS

5.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.86

gMVP

0.88

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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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