rs541282922

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP4_StrongBP6_Very_StrongBS2

The NM_000742.4(CHRNA2):​c.347G>T​(p.Ser116Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000127 in 1,610,348 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S116R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00014 ( 5 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

19

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: -0.376

Publications

1 publications found
Variant links:
Genes affected
CHRNA2 (HGNC:1956): (cholinergic receptor nicotinic alpha 2 subunit) Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels formed by a pentameric arrangement of alpha and beta subunits to create distinct muscle and neuronal receptors. Neuronal receptors are found throughout the peripheral and central nervous system where they are involved in fast synaptic transmission. This gene encodes an alpha subunit that is widely expressed in the brain. The proposed structure for nAChR subunits is a conserved N-terminal extracellular domain followed by three conserved transmembrane domains, a variable cytoplasmic loop, a fourth conserved transmembrane domain, and a short C-terminal extracellular region. Mutations in this gene cause autosomal dominant nocturnal frontal lobe epilepsy type 4. Single nucleotide polymorphisms (SNPs) in this gene have been associated with nicotine dependence. [provided by RefSeq, Nov 2009]
CHRNA2 Gene-Disease associations (from GenCC):
  • autosomal dominant nocturnal frontal lobe epilepsy 4
    Inheritance: AD Classification: STRONG, LIMITED Submitted by: G2P, Illumina, Labcorp Genetics (formerly Invitae)
  • autosomal dominant nocturnal frontal lobe epilepsy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial sleep-related hypermotor epilepsy
    Inheritance: AD Classification: LIMITED Submitted by: ClinGen
  • benign familial infantile epilepsy
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -16 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.050329536).
BP6
Variant 8-27467331-C-A is Benign according to our data. Variant chr8-27467331-C-A is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 204945.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS2
High AC in GnomAd4 at 8 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA2NM_000742.4 linkc.347G>T p.Ser116Ile missense_variant Exon 5 of 7 ENST00000407991.3 NP_000733.2 Q15822-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNA2ENST00000407991.3 linkc.347G>T p.Ser116Ile missense_variant Exon 5 of 7 5 NM_000742.4 ENSP00000385026.1 Q15822-1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152226
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:
0.00145
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000270
AC:
68
AN:
251448
AF XY:
0.000375
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000867
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:
0.000135
AC:
197
AN:
1458004
Hom.:
5
Cov.:
30
AF XY:
0.000208
AC XY:
151
AN XY:
725528
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33274
American (AMR)
AF:
0.0000895
AC:
4
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26114
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39630
South Asian (SAS)
AF:
0.00212
AC:
183
AN:
86172
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.000695
AC:
4
AN:
5756
European-Non Finnish (NFE)
AF:
9.02e-7
AC:
1
AN:
1108708
Other (OTH)
AF:
0.0000830
AC:
5
AN:
60228
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.496
Heterozygous variant carriers
0
13
26
39
52
65
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:
0.0000525
AC:
8
AN:
152344
Hom.:
0
Cov.:
32
AF XY:
0.0000806
AC XY:
6
AN XY:
74482
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41584
American (AMR)
AF:
0.00
AC:
0
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.00145
AC:
7
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.519
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.000136
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.000272
AC:
33
Asia WGS
AF:
0.000577
AC:
2
AN:
3478

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy Benign:1
Oct 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
Dec 21, 2020
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

CHRNA2-related disorder Benign:1
Jul 01, 2019
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
-0.46
T
BayesDel_noAF
Benign
-0.44
CADD
Benign
6.5
DANN
Benign
0.31
DEOGEN2
Benign
0.36
T;.;.
Eigen
Benign
-1.5
Eigen_PC
Benign
-1.5
FATHMM_MKL
Benign
0.083
N
LIST_S2
Benign
0.70
T;T;T
M_CAP
Benign
0.024
T
MetaRNN
Benign
0.050
T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
-0.17
N;.;.
PhyloP100
-0.38
PrimateAI
Benign
0.43
T
PROVEAN
Benign
-1.9
N;.;N
REVEL
Benign
0.094
Sift
Benign
0.34
T;.;T
Sift4G
Benign
0.54
T;T;T
Polyphen
0.0040
B;.;.
Vest4
0.45
MutPred
0.33
Gain of methylation at K119 (P = 0.0786);.;.;
MVP
0.53
MPC
0.52
ClinPred
0.025
T
GERP RS
-5.6
Varity_R
0.11
gMVP
0.43
Mutation Taster
=81/19
polymorphism

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: rs541282922; hg19: chr8-27324848; API