2-174748178-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_000079.4(CHRNA1):​c.1320C>G​(p.Ile440Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,972 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I440T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

CHRNA1
NM_000079.4 missense

Scores

9
10

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -0.110

Publications

0 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000079.4
PM2
Very rare variant in population databases, with high coverage;
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 UniProt
CHRNA1NM_000079.4 linkc.1320C>G p.Ile440Met missense_variant Exon 9 of 9 ENST00000348749.9 NP_000070.1 P02708-2Q53SH4
CHRNA1NM_001039523.3 linkc.1395C>G p.Ile465Met missense_variant Exon 10 of 10 NP_001034612.1 P02708-1Q53SH4
CHRNA1XM_017003256.2 linkc.1416C>G p.Ile472Met missense_variant Exon 9 of 9 XP_016858745.1
CHRNA1XM_017003257.2 linkc.1341C>G p.Ile447Met missense_variant Exon 8 of 8 XP_016858746.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNA1ENST00000348749.9 linkc.1320C>G p.Ile440Met missense_variant Exon 9 of 9 1 NM_000079.4 ENSP00000261008.5 P02708-2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152102
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461870
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
727242
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53406
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.00000657
AC:
1
AN:
152102
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74308
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41384
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Uncertain
0.16
D
BayesDel_noAF
Uncertain
-0.010
CADD
Benign
18
DANN
Benign
0.97
DEOGEN2
Benign
0.40
.;T;T;T;T
Eigen
Benign
-0.17
Eigen_PC
Benign
-0.34
FATHMM_MKL
Benign
0.54
D
LIST_S2
Uncertain
0.89
D;D;D;D;D
M_CAP
Uncertain
0.097
D
MetaRNN
Uncertain
0.60
D;D;D;D;D
MetaSVM
Uncertain
0.20
D
MutationAssessor
Uncertain
2.4
.;M;.;.;.
PhyloP100
-0.11
PrimateAI
Uncertain
0.65
T
PROVEAN
Benign
-0.77
N;N;N;N;.
REVEL
Uncertain
0.59
Sift
Benign
0.030
D;D;D;D;.
Sift4G
Benign
0.071
T;T;D;D;.
Polyphen
1.0
.;D;.;.;.
Vest4
0.57
MutPred
0.58
.;Gain of helix (P = 0.132);.;.;.;
MVP
0.74
MPC
0.91
ClinPred
0.92
D
GERP RS
-4.7
Varity_R
0.47
gMVP
0.59
Mutation Taster
=40/60
disease causing

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

Other links and lift over

dbSNP: rs776420240; hg19: chr2-175612906; API