rs137916282

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP2

The NM_000079.4(CHRNA1):c.1199A>G(p.Lys400Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,613,990 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

CHRNA1
NM_000079.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.95

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: Uncertain_significance. The variant received 1 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein
CHRNA1	NM_000079.4 link	c.1199A>G	p.Lys400Arg	missense_variant	Exon 8 of 9	ENST00000348749.9	NP_000070.1
CHRNA1	NM_001039523.3 link	c.1274A>G	p.Lys425Arg	missense_variant	Exon 9 of 10		NP_001034612.1
CHRNA1	XM_017003256.2 link	c.1295A>G	p.Lys432Arg	missense_variant	Exon 8 of 9		XP_016858745.1
CHRNA1	XM_017003257.2 link	c.1220A>G	p.Lys407Arg	missense_variant	Exon 7 of 8		XP_016858746.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNA1	ENST00000348749.9 link	c.1199A>G	p.Lys400Arg	missense_variant	Exon 8 of 9	1	NM_000079.4	ENSP00000261008.5

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.000478

GnomAD2 exomes

AF:

0.0000119

AC:

AN:

251292

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000290

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:

0.00000479

AC:

AN:

1461780

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727174

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44710

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

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:

1111924

Other (OTH)

AF:

0.00

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.482

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:

0.0000657

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74346

show subpopulations

African (AFR)

AF:

0.000145

AC:

AN:

41448

American (AMR)

AF:

0.0000654

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3464

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68050

Other (OTH)

AF:

0.000478

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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:

0.000132

Hom.:

Bravo

AF:

0.0000756

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Mar 03, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.1199A>G (p.K400R) alteration is located in exon 8 (coding exon 8) of the CHRNA1 gene. This alteration results from a A to G substitution at nucleotide position 1199, causing the lysine (K) at amino acid position 400 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Lethal multiple pterygium syndrome

Uncertain:1

Feb 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 400 of the CHRNA1 protein (p.Lys400Arg). This variant is present in population databases (rs137916282, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with CHRNA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 534527). 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 CHRNA1 protein function with a negative predictive value of 80%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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

Benign

0.089

BayesDel_addAF

Uncertain

0.022

BayesDel_noAF

Uncertain

0.030

CADD

Pathogenic

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.34

.;T;T;T

Eigen

Uncertain

0.42

Eigen_PC

Uncertain

0.49

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.91

D;D;D;D

M_CAP

Benign

0.058

MetaRNN

Uncertain

0.50

D;D;D;D

MetaSVM

Uncertain

-0.16

MutationAssessor

Benign

0.88

.;L;.;.

PhyloP100

8.0

PrimateAI

Uncertain

0.70

PROVEAN

Benign

-0.63

N;N;N;.

REVEL

Uncertain

0.54

Sift

Benign

1.0

T;T;T;.

Sift4G

Benign

1.0

T;T;T;.

Polyphen

0.99

.;D;.;.

Vest4

0.72

MVP

0.85

MPC

0.79

ClinPred

0.51

GERP RS

5.5

Varity_R

0.33

gMVP

0.62

Mutation Taster

=17/83

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.49

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.49

Position offset: 0

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