rs768407867

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PP2PP3_ModeratePP5_Very_Strong

The NM_000079.4(CHRNA1):c.1321G>A(p.Gly441Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000198 in 1,613,956 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CHRNA1
NM_000079.4 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.91

Publications

3 publications found

Variant links:

Genes affected

CHRNA1 (HGNC:1955): (cholinergic receptor nicotinic alpha 1 subunit) The muscle acetylcholine receptor consiststs of 5 subunits of 4 different types: 2 alpha subunits and 1 each of the beta, gamma, and delta subunits. This gene encodes an alpha subunit that plays a role in acetlycholine binding/channel gating. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Nov 2012]

CHRNA1 Gene-Disease associations (from GenCC):

congenital myasthenic syndrome 1A
Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
lethal multiple pterygium syndrome
Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, G2P
myasthenic syndrome, congenital, 1B, fast-channel
Inheritance: AR, AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, PanelApp Australia
postsynaptic congenital myasthenic syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

CHRNA1 links:

ENSG00000236449 (HGNC:):

ENSG00000236449 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 16 curated pathogenic missense variants (we use a threshold of 10). The gene has 5 curated benign missense variants. Gene score misZ: 0.72157 (below the threshold of 3.09). Trascript score misZ: 1.6771 (below the threshold of 3.09). GenCC associations: The gene is linked to lethal multiple pterygium syndrome, congenital myasthenic syndrome 1A, myasthenic syndrome, congenital, 1B, fast-channel, postsynaptic congenital myasthenic syndrome.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.873

PP5

Variant 2-174748177-C-T is Pathogenic according to our data. Variant chr2-174748177-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 449923.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNA1	NM_000079.4 link	c.1321G>A	p.Gly441Arg	missense_variant	Exon 9 of 9	ENST00000348749.9	NP_000070.1	P02708-2Q53SH4
CHRNA1	NM_001039523.3 link	c.1396G>A	p.Gly466Arg	missense_variant	Exon 10 of 10		NP_001034612.1	P02708-1Q53SH4
CHRNA1	XM_017003256.2 link	c.1417G>A	p.Gly473Arg	missense_variant	Exon 9 of 9		XP_016858745.1
CHRNA1	XM_017003257.2 link	c.1342G>A	p.Gly448Arg	missense_variant	Exon 8 of 8		XP_016858746.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNA1	ENST00000348749.9 link	c.1321G>A	p.Gly441Arg	missense_variant	Exon 9 of 9	1	NM_000079.4	ENSP00000261008.5		P02708-2

Frequencies

GnomAD3 genomes

AF:

0.0000395

AC:

AN:

152090

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000967

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000438

AC:

AN:

251230

AF XY:

0.00000737

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.000260

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000178

AC:

AN:

1461866

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727238

show subpopulations

African (AFR)

AF:

0.0000597

AC:

AN:

33476

American (AMR)

AF:

0.000201

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53410

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000135

AC:

AN:

1112004

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.442

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:

0.0000395

AC:

AN:

152090

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74286

show subpopulations

African (AFR)

AF:

0.0000967

AC:

AN:

41384

American (AMR)

AF:

0.00

AC:

AN:

15276

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5188

South Asian (SAS)

AF:

0.00

AC:

AN:

4816

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10610

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68032

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.483

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:

0.0000987

Hom.:

Bravo

AF:

0.0000680

ExAC

AF:

0.0000412

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:3

Oct 08, 2021

Athena Diagnostics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant appears to segregate with disease in at least one family (PMID: 27748205). Assessment of experimental evidence suggests this variant results in abnormal protein function (PMID: 24121633). The frequency of this variant in the general population is consistent with pathogenicity (http://gnomad.broadinstitute.org).This observation is not an independent occurrence and has been identified in the same individual by RCIGM, the other laboratory participating in the GEMINI study. -

Apr 28, 2022

Revvity Omics, Revvity

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Mar 30, 2025

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Published functional studies demonstrate reduced expression as compared to wild-type protein (PMID: 24121633); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 27748205, 24121633, 34749429, 36007526, 37432431, 39677241) -

Lethal multiple pterygium syndrome

Pathogenic:1

Oct 06, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 441 of the CHRNA1 protein (p.Gly441Arg). This variant is present in population databases (rs768407867, gnomAD 0.03%). This missense change has been observed in individual(s) with autosomal recessive severe congenital myasthenic syndrome (PMID: 24121633, 27748205; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. This variant is also known as p.Gly421Arg and p.Gly466Arg. ClinVar contains an entry for this variant (Variation ID: 449923). 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 expected to disrupt CHRNA1 protein function. Experimental studies have shown that this missense change affects CHRNA1 function (PMID: 24121633). For these reasons, this variant has been classified as Pathogenic. -

Autism;C0036572:Seizure

Pathogenic:1

Mar 24, 2017

Clinical Molecular Genetics Laboratory, Johns Hopkins All Children's Hospital

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Centronuclear myopathy

Pathogenic:1

Mar 01, 2024

Muscle and Diseases Team, Institut de Génétique et Biologie Moléculaire et Cellulaire

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

PS3+PM1+PM2+PP2+PP3+PP4+PP5 -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.26

BayesDel_noAF

Pathogenic

0.43

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.93

.;D;D;T;T

Eigen

Pathogenic

0.99

Eigen_PC

Pathogenic

0.90

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.97

D;D;D;D;D

M_CAP

Pathogenic

0.42

MetaRNN

Pathogenic

0.87

D;D;D;D;D

MetaSVM

Pathogenic

0.99

MutationAssessor

Pathogenic

3.3

.;M;.;.;.

PhyloP100

7.9

PrimateAI

Pathogenic

0.89

PROVEAN

Pathogenic

-7.1

D;D;D;N;.

REVEL

Pathogenic

0.95

Sift

Pathogenic

0.0

D;D;D;D;.

Sift4G

Pathogenic

0.0

D;D;D;D;.

Polyphen

1.0

.;D;.;.;.

Vest4

0.84

MutPred

0.94

.;Gain of helix (P = 0.132);.;.;.;

MVP

0.93

MPC

1.0

ClinPred

0.89

GERP RS

5.2

Varity_R

0.97

gMVP

0.95

Mutation Taster

=5/95

disease causing (ClinVar)

(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

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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