rs1060503072

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS2

The NM_000742.4(CHRNA2):​c.1180C>T​(p.Arg394Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000686 in 1,604,648 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R394H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

3
16

Clinical Significance

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

Conservation

PhyloP100: 1.85

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.23733565).
BP6
Variant 8-27463263-G-A is Benign according to our data. Variant chr8-27463263-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 410916.
BS2
High AC in GnomAdExome4 at 9 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA2NM_000742.4 linkc.1180C>T p.Arg394Cys 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.1180C>T p.Arg394Cys missense_variant Exon 6 of 7 5 NM_000742.4 ENSP00000385026.1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152204
Hom.:
0
Cov.:
33
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000123
AC:
3
AN:
244260
AF XY:
0.00000759
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000183
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000620
AC:
9
AN:
1452444
Hom.:
0
Cov.:
32
AF XY:
0.00000832
AC XY:
6
AN XY:
720980
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33358
American (AMR)
AF:
0.00
AC:
0
AN:
44480
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25532
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39564
South Asian (SAS)
AF:
0.0000235
AC:
2
AN:
85212
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52830
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5724
European-Non Finnish (NFE)
AF:
0.00000633
AC:
7
AN:
1105802
Other (OTH)
AF:
0.00
AC:
0
AN:
59942
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000131
AC:
2
AN:
152204
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74352
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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:
0.0000572
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Nov 20, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1180C>T (p.R394C) alteration is located in exon 6 (coding exon 5) of the CHRNA2 gene. This alteration results from a C to T substitution at nucleotide position 1180, causing the arginine (R) at amino acid position 394 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Autosomal dominant nocturnal frontal lobe epilepsy Benign:1
Jan 30, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.078
BayesDel_addAF
Benign
-0.28
T
BayesDel_noAF
Benign
-0.53
CADD
Benign
17
DANN
Benign
0.92
DEOGEN2
Benign
0.36
T;.;.
Eigen
Benign
-0.74
Eigen_PC
Benign
-0.84
FATHMM_MKL
Benign
0.17
N
LIST_S2
Benign
0.52
T;T;T
M_CAP
Uncertain
0.12
D
MetaRNN
Benign
0.24
T;T;T
MetaSVM
Benign
-0.77
T
MutationAssessor
Benign
0.43
N;.;.
PhyloP100
1.8
PrimateAI
Benign
0.23
T
PROVEAN
Benign
-1.1
N;.;N
REVEL
Benign
0.23
Sift
Uncertain
0.026
D;.;D
Sift4G
Uncertain
0.025
D;D;D
Polyphen
0.11
B;.;.
Vest4
0.093
MutPred
0.67
Loss of solvent accessibility (P = 0.0079);.;.;
MVP
0.73
MPC
0.41
ClinPred
0.17
T
GERP RS
3.3
Varity_R
0.097
gMVP
0.43
Mutation Taster
=97/3
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: rs1060503072; hg19: chr8-27320780; COSMIC: COSV99532351; COSMIC: COSV99532351; API