rs138682847

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2

The NM_000742.4(CHRNA2):​c.383G>A​(p.Gly128Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000898 in 1,614,046 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00054 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000043 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

1
17

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:5

Conservation

PhyloP100: 2.68

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
  • 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 -9 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.031199813).
BP6
Variant 8-27467295-C-T is Benign according to our data. Variant chr8-27467295-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 197689.
BS2
High AC in GnomAd4 at 82 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000742.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHRNA2
NM_000742.4
MANE Select
c.383G>Ap.Gly128Asp
missense
Exon 5 of 7NP_000733.2Q15822-1
CHRNA2
NM_001282455.2
c.338G>Ap.Gly113Asp
missense
Exon 5 of 7NP_001269384.1Q15822-2
CHRNA2
NM_001347705.2
c.-90G>A
5_prime_UTR
Exon 5 of 7NP_001334634.1

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHRNA2
ENST00000407991.3
TSL:5 MANE Select
c.383G>Ap.Gly128Asp
missense
Exon 5 of 7ENSP00000385026.1Q15822-1
CHRNA2
ENST00000520600.1
TSL:1
n.223G>A
non_coding_transcript_exon
Exon 1 of 2
CHRNA2
ENST00000523695.5
TSL:1
n.383G>A
non_coding_transcript_exon
Exon 5 of 7ENSP00000430612.1E5RJ54

Frequencies

GnomAD3 genomes
AF:
0.000539
AC:
82
AN:
152210
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00125
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00177
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:
0.00143
GnomAD2 exomes
AF:
0.000107
AC:
27
AN:
251486
AF XY:
0.0000956
show subpopulations
Gnomad AFR exome
AF:
0.00123
Gnomad AMR exome
AF:
0.000116
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:
0.000489
GnomAD4 exome
AF:
0.0000431
AC:
63
AN:
1461718
Hom.:
0
Cov.:
30
AF XY:
0.0000358
AC XY:
26
AN XY:
727176
show subpopulations
African (AFR)
AF:
0.00131
AC:
44
AN:
33470
American (AMR)
AF:
0.000201
AC:
9
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111866
Other (OTH)
AF:
0.000149
AC:
9
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.419
Heterozygous variant carriers
0
4
8
12
16
20
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:
0.000538
AC:
82
AN:
152328
Hom.:
0
Cov.:
33
AF XY:
0.000497
AC XY:
37
AN XY:
74480
show subpopulations
African (AFR)
AF:
0.00125
AC:
52
AN:
41580
American (AMR)
AF:
0.00176
AC:
27
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68024
Other (OTH)
AF:
0.00142
AC:
3
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.509
Heterozygous variant carriers
0
5
10
14
19
24
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:
0.000251
Hom.:
0
Bravo
AF:
0.000714
ESP6500AA
AF:
0.00136
AC:
6
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000132
AC:
16

ClinVar

ClinVar submissions
Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
1
3
not provided (4)
-
-
1
Autosomal dominant nocturnal frontal lobe epilepsy (1)
-
1
-
Autosomal dominant nocturnal frontal lobe epilepsy 4 (1)
-
-
1
Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.19
BayesDel_addAF
Benign
-0.39
T
BayesDel_noAF
Benign
-0.37
CADD
Benign
17
DANN
Benign
0.90
DEOGEN2
Benign
0.24
T
Eigen
Benign
-0.34
Eigen_PC
Benign
-0.21
FATHMM_MKL
Benign
0.66
D
LIST_S2
Benign
0.69
T
M_CAP
Benign
0.019
T
MetaRNN
Benign
0.031
T
MetaSVM
Benign
-0.78
T
MutationAssessor
Benign
0.17
N
PhyloP100
2.7
PrimateAI
Uncertain
0.64
T
PROVEAN
Benign
0.99
N
REVEL
Benign
0.18
Sift
Benign
0.50
T
Sift4G
Benign
0.47
T
Polyphen
0.0080
B
Vest4
0.27
MVP
0.87
MPC
0.24
ClinPred
0.023
T
GERP RS
3.7
Varity_R
0.29
gMVP
0.67
Mutation Taster
=47/53
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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: rs138682847; hg19: chr8-27324812; API