rs140268343

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 1P and 2B. PP2BP4BS1_Supporting

The NM_000079.4(CHRNA1):​c.319C>T​(p.Arg107Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000632 in 1,613,908 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R107H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000049 ( 0 hom. )

Consequence

CHRNA1
NM_000079.4 missense

Scores

1
7
10

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 3.10

Publications

4 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: Likely_benign. 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.
BP4
Computational evidence support a benign effect (MetaRNN=0.33875126).
BS1
Variant frequency is greater than expected in population afr. GnomAdExome4 allele frequency = 0.0000486 (71/1461656) while in subpopulation AFR AF = 0.000986 (33/33476). AF 95% confidence interval is 0.000721. There are 0 homozygotes in GnomAdExome4. There are 40 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000079.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHRNA1
NM_000079.4
MANE Select
c.319C>Tp.Arg107Cys
missense
Exon 4 of 9NP_000070.1
CHRNA1
NM_001039523.3
c.394C>Tp.Arg132Cys
missense
Exon 5 of 10NP_001034612.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHRNA1
ENST00000348749.9
TSL:1 MANE Select
c.319C>Tp.Arg107Cys
missense
Exon 4 of 9ENSP00000261008.5
CHRNA1
ENST00000409323.1
TSL:1
c.319C>Tp.Arg107Cys
missense
Exon 4 of 6ENSP00000386684.1
ENSG00000236449
ENST00000442996.1
TSL:1
n.322-15158G>A
intron
N/A

Frequencies

GnomAD3 genomes
AF:
0.000204
AC:
31
AN:
152134
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000676
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:
0.00
GnomAD2 exomes
AF:
0.0000557
AC:
14
AN:
251368
AF XY:
0.0000736
show subpopulations
Gnomad AFR exome
AF:
0.000369
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000163
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000486
AC:
71
AN:
1461656
Hom.:
0
Cov.:
31
AF XY:
0.0000550
AC XY:
40
AN XY:
727146
show subpopulations
African (AFR)
AF:
0.000986
AC:
33
AN:
33476
American (AMR)
AF:
0.000112
AC:
5
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.000202
AC:
8
AN:
39696
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000198
AC:
22
AN:
1111804
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60384
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.460
Heterozygous variant carriers
0
4
8
13
17
21
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.000204
AC:
31
AN:
152252
Hom.:
0
Cov.:
32
AF XY:
0.000242
AC XY:
18
AN XY:
74440
show subpopulations
African (AFR)
AF:
0.000674
AC:
28
AN:
41542
American (AMR)
AF:
0.0000654
AC:
1
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10586
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.491
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000944
Hom.:
1
Bravo
AF:
0.000193
ESP6500AA
AF:
0.000454
AC:
2
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000412
AC:
5

ClinVar

ClinVar submissions as Germline

Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
1
1
Lethal multiple pterygium syndrome (2)
-
1
-
Congenital myasthenic syndrome (1)
-
1
-
Inborn genetic diseases (1)
-
1
-
Juvenile myoclonic epilepsy (1)
-
1
-
not provided (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.41
BayesDel_addAF
Benign
-0.24
T
BayesDel_noAF
Benign
-0.16
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.66
D
Eigen
Benign
0.19
Eigen_PC
Uncertain
0.35
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.94
D
M_CAP
Benign
0.054
D
MetaRNN
Benign
0.34
T
MetaSVM
Benign
-0.30
T
MutationAssessor
Uncertain
2.5
M
PhyloP100
3.1
PrimateAI
Benign
0.31
T
PROVEAN
Benign
-2.1
N
REVEL
Uncertain
0.45
Sift
Benign
0.084
T
Sift4G
Benign
0.086
T
Polyphen
0.0010
B
Vest4
0.60
MVP
0.77
MPC
0.34
ClinPred
0.078
T
GERP RS
6.1
Varity_R
0.55
gMVP
0.72
Mutation Taster
=47/53
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: rs140268343; hg19: chr2-175622319; API