chr2-174750143-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PP3BS1_Supporting

The NM_000079.4(CHRNA1):​c.805G>C​(p.Val269Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000441 in 1,608,632 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 (★★).

Frequency

Genomes: 𝑓 0.00019 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

CHRNA1
NM_000079.4 missense

Scores

7
9
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.91
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.767
BS1
Variant frequency is greater than expected in population afr. gnomad4_exome allele frequency = 0.0000295 (43/1460066) while in subpopulation AFR AF= 0.000958 (32/33420). AF 95% confidence interval is 0.000696. There are 0 homozygotes in gnomad4_exome. There are 16 alleles in male gnomad4_exome subpopulation. Median coverage is 34. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA1NM_000079.4 linkc.805G>C p.Val269Leu missense_variant Exon 7 of 9 ENST00000348749.9 NP_000070.1 P02708-2Q53SH4
CHRNA1NM_001039523.3 linkc.880G>C p.Val294Leu missense_variant Exon 8 of 10 NP_001034612.1 P02708-1Q53SH4
CHRNA1XM_017003256.2 linkc.901G>C p.Val301Leu missense_variant Exon 7 of 9 XP_016858745.1
CHRNA1XM_017003257.2 linkc.826G>C p.Val276Leu missense_variant Exon 6 of 8 XP_016858746.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNA1ENST00000348749.9 linkc.805G>C p.Val269Leu missense_variant Exon 7 of 9 1 NM_000079.4 ENSP00000261008.5 P02708-2

Frequencies

GnomAD3 genomes
AF:
0.000189
AC:
28
AN:
148452
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.000651
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000135
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000280
AC:
7
AN:
250270
Hom.:
0
AF XY:
0.0000369
AC XY:
5
AN XY:
135334
show subpopulations
Gnomad AFR exome
AF:
0.000309
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000295
AC:
43
AN:
1460066
Hom.:
0
Cov.:
34
AF XY:
0.0000220
AC XY:
16
AN XY:
726362
show subpopulations
Gnomad4 AFR exome
AF:
0.000958
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.000133
GnomAD4 genome
AF:
0.000188
AC:
28
AN:
148566
Hom.:
0
Cov.:
31
AF XY:
0.000152
AC XY:
11
AN XY:
72272
show subpopulations
Gnomad4 AFR
AF:
0.000649
Gnomad4 AMR
AF:
0.000135
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000138
Hom.:
0
Bravo
AF:
0.000280
ExAC
AF:
0.0000330
AC:
4
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Lethal multiple pterygium syndrome Uncertain:2
Oct 26, 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 leucine, which is neutral and non-polar, at codon 269 of the CHRNA1 protein (p.Val269Leu). This variant is present in population databases (no rsID available, gnomAD 0.04%). 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: 892724). 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 CHRNA1 protein function with a negative predictive value of 80%. This variant disrupts the p.Val269 (also known as p.Val249) amino acid residue in CHRNA1. Other variant(s) that disrupt this residue have been observed in individuals with CHRNA1-related conditions (PMID: 9221765, 33216040), which suggests that this may be a clinically significant amino acid residue. 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. -

Apr 28, 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. -

Congenital myasthenic syndrome Uncertain:1
Apr 28, 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
Pathogenic
0.90
BayesDel_addAF
Uncertain
0.13
D
BayesDel_noAF
Pathogenic
0.30
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.76
.;D;D;D;T
Eigen
Uncertain
0.67
Eigen_PC
Pathogenic
0.71
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.96
D;D;D;D;D
M_CAP
Uncertain
0.13
D
MetaRNN
Pathogenic
0.77
D;D;D;D;D
MetaSVM
Uncertain
0.53
D
MutationAssessor
Benign
1.9
.;L;.;.;.
PrimateAI
Pathogenic
0.90
D
PROVEAN
Uncertain
-2.6
D;D;N;D;.
REVEL
Pathogenic
0.85
Sift
Benign
0.041
D;D;D;D;.
Sift4G
Uncertain
0.019
D;D;D;D;.
Polyphen
0.98
.;D;.;.;.
Vest4
0.79
MVP
0.81
MPC
0.46
ClinPred
0.28
T
GERP RS
5.6
Varity_R
0.62
gMVP
0.89

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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.

Other links and lift over

dbSNP: rs137852803; hg19: chr2-175614871; COSMIC: COSV53681846; COSMIC: COSV53681846; API