rs751699392

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PP3_ModerateBP6BS2

The NM_000742.4(CHRNA2):​c.1099C>T​(p.Arg367Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,613,778 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R367Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

6
5
7

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:4

Conservation

PhyloP100: 1.46

Publications

0 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: Likely_benign. The variant received -3 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.935
BP6
Variant 8-27463344-G-A is Benign according to our data. Variant chr8-27463344-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 362695.
BS2
High AC in GnomAd4 at 10 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.1099C>Tp.Arg367Trp
missense
Exon 6 of 7NP_000733.2Q15822-1
CHRNA2
NM_001282455.2
c.1054C>Tp.Arg352Trp
missense
Exon 6 of 7NP_001269384.1Q15822-2
CHRNA2
NM_001347705.2
c.622C>Tp.Arg208Trp
missense
Exon 6 of 7NP_001334634.1

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CHRNA2
ENST00000407991.3
TSL:5 MANE Select
c.1099C>Tp.Arg367Trp
missense
Exon 6 of 7ENSP00000385026.1Q15822-1
CHRNA2
ENST00000523695.5
TSL:1
n.*501C>T
non_coding_transcript_exon
Exon 6 of 7ENSP00000430612.1E5RJ54
CHRNA2
ENST00000523695.5
TSL:1
n.*501C>T
3_prime_UTR
Exon 6 of 7ENSP00000430612.1E5RJ54

Frequencies

GnomAD3 genomes
AF:
0.0000657
AC:
10
AN:
152176
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000524
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:
0.00
GnomAD2 exomes
AF:
0.0000762
AC:
19
AN:
249216
AF XY:
0.0000519
show subpopulations
Gnomad AFR exome
AF:
0.0000622
Gnomad AMR exome
AF:
0.000318
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.000139
Gnomad NFE exome
AF:
0.00000893
Gnomad OTH exome
AF:
0.000329
GnomAD4 exome
AF:
0.0000198
AC:
29
AN:
1461602
Hom.:
0
Cov.:
32
AF XY:
0.0000193
AC XY:
14
AN XY:
727066
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.000380
AC:
17
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:
86256
European-Finnish (FIN)
AF:
0.0000188
AC:
1
AN:
53164
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000630
AC:
7
AN:
1111984
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.499
Heterozygous variant carriers
0
3
5
8
10
13
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:
0.0000657
AC:
10
AN:
152176
Hom.:
0
Cov.:
33
AF XY:
0.0000807
AC XY:
6
AN XY:
74350
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41442
American (AMR)
AF:
0.000524
AC:
8
AN:
15280
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:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000508
Hom.:
0
Bravo
AF:
0.0000907
ExAC
AF:
0.0000494
AC:
6

ClinVar

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

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.18
BayesDel_addAF
Benign
-0.15
T
BayesDel_noAF
Benign
-0.15
CADD
Benign
21
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.93
D
Eigen
Benign
0.13
Eigen_PC
Benign
-0.14
FATHMM_MKL
Benign
0.67
D
LIST_S2
Uncertain
0.94
D
M_CAP
Uncertain
0.086
D
MetaRNN
Pathogenic
0.94
D
MetaSVM
Uncertain
0.69
D
MutationAssessor
Pathogenic
4.5
H
PhyloP100
1.5
PrimateAI
Benign
0.44
T
PROVEAN
Pathogenic
-6.4
D
REVEL
Uncertain
0.51
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.72
MVP
0.88
MPC
0.72
ClinPred
0.98
D
GERP RS
-0.77
Varity_R
0.69
gMVP
0.74
Mutation Taster
=83/17
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: rs751699392; hg19: chr8-27320861; API