8-27463733-G-T

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.710C>A​(p.Thr237Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000948 in 1,614,056 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 Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. T237T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00047 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000055 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

6
13

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 6.51

Publications

2 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=0.059072375).
BP6
Variant 8-27463733-G-T is Benign according to our data. Variant chr8-27463733-G-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 204963.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS2
High AC in GnomAd4 at 72 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA2NM_000742.4 linkc.710C>A p.Thr237Lys missense_variant Exon 6 of 7 ENST00000407991.3 NP_000733.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNA2ENST00000407991.3 linkc.710C>A p.Thr237Lys missense_variant Exon 6 of 7 5 NM_000742.4 ENSP00000385026.1

Frequencies

GnomAD3 genomes
AF:
0.000474
AC:
72
AN:
152048
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00162
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.00144
GnomAD2 exomes
AF:
0.000119
AC:
30
AN:
251488
AF XY:
0.0000883
show subpopulations
Gnomad AFR exome
AF:
0.00148
Gnomad AMR exome
AF:
0.000173
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:
0.0000554
AC:
81
AN:
1461890
Hom.:
0
Cov.:
33
AF XY:
0.0000399
AC XY:
29
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00203
AC:
68
AN:
33480
American (AMR)
AF:
0.000134
AC:
6
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112012
Other (OTH)
AF:
0.0000828
AC:
5
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.476
Heterozygous variant carriers
0
8
16
23
31
39
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:
0.000473
AC:
72
AN:
152166
Hom.:
0
Cov.:
32
AF XY:
0.000376
AC XY:
28
AN XY:
74406
show subpopulations
African (AFR)
AF:
0.00161
AC:
67
AN:
41508
American (AMR)
AF:
0.000131
AC:
2
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5168
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67992
Other (OTH)
AF:
0.00142
AC:
3
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.511
Heterozygous variant carriers
0
5
10
16
21
26
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:
0.000154
Hom.:
0
Bravo
AF:
0.000514
ESP6500AA
AF:
0.00113
AC:
5
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000107
AC:
13
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:2
-
Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Jun 25, 2019
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal dominant nocturnal frontal lobe epilepsy Benign:1
Dec 10, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

CHRNA2-related disorder Benign:1
Mar 24, 2023
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
0.12
BayesDel_addAF
Benign
-0.30
T
BayesDel_noAF
Benign
-0.22
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Benign
0.28
T;.;.
Eigen
Uncertain
0.38
Eigen_PC
Uncertain
0.45
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Benign
0.70
T;T;T
M_CAP
Benign
0.058
D
MetaRNN
Benign
0.059
T;T;T
MetaSVM
Benign
-0.60
T
MutationAssessor
Benign
-0.13
N;.;.
PhyloP100
6.5
PrimateAI
Uncertain
0.54
T
PROVEAN
Benign
-0.92
N;.;N
REVEL
Uncertain
0.34
Sift
Benign
0.12
T;.;T
Sift4G
Benign
0.064
T;T;T
Polyphen
0.89
P;.;.
Vest4
0.38
MVP
0.85
MPC
0.77
ClinPred
0.091
T
GERP RS
4.0
Varity_R
0.24
gMVP
0.72
Mutation Taster
=56/44
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: rs140350483; hg19: chr8-27321250; API