rs150451372

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000744.7(CHRNA4):​c.181G>T​(p.Val61Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000197 in 152,240 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V61M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 34)

Consequence

CHRNA4
NM_000744.7 missense

Scores

5
14

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.71

Publications

1 publications found
Variant links:
Genes affected
CHRNA4 (HGNC:1958): (cholinergic receptor nicotinic alpha 4 subunit) This gene encodes a nicotinic acetylcholine receptor, which belongs to a superfamily of ligand-gated ion channels that play a role in fast signal transmission at synapses. These pentameric receptors can bind acetylcholine, which causes an extensive change in conformation that leads to the opening of an ion-conducting channel across the plasma membrane. This protein is an integral membrane receptor subunit that can interact with either nAChR beta-2 or nAChR beta-4 to form a functional receptor. Mutations in this gene cause nocturnal frontal lobe epilepsy type 1. Polymorphisms in this gene that provide protection against nicotine addiction have been described. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2012]
CHRNA4 Gene-Disease associations (from GenCC):
  • autosomal dominant nocturnal frontal lobe epilepsy 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • familial sleep-related hypermotor epilepsy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • autosomal dominant nocturnal frontal lobe epilepsy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA4NM_000744.7 linkc.181G>T p.Val61Leu missense_variant Exon 2 of 6 ENST00000370263.9 NP_000735.1 P43681-1B4DK78Q59FV0
CHRNA4NM_001256573.2 linkc.-366G>T 5_prime_UTR_premature_start_codon_gain_variant Exon 2 of 6 NP_001243502.1 P43681Q4VAQ3B4DK78Q59FV0
CHRNA4NR_046317.2 linkn.365G>T non_coding_transcript_exon_variant Exon 2 of 6
CHRNA4NM_001256573.2 linkc.-366G>T 5_prime_UTR_variant Exon 2 of 6 NP_001243502.1 P43681Q4VAQ3B4DK78Q59FV0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNA4ENST00000370263.9 linkc.181G>T p.Val61Leu missense_variant Exon 2 of 6 1 NM_000744.7 ENSP00000359285.4 P43681-1

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152240
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.0000724
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
37
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152240
Hom.:
0
Cov.:
34
AF XY:
0.0000269
AC XY:
2
AN XY:
74376
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41458
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
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:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.442
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.0000189

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy Uncertain:1
Oct 14, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on CHRNA4 protein function. ClinVar contains an entry for this variant (Variation ID: 543522). This variant has not been reported in the literature in individuals affected with CHRNA4-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 61 of the CHRNA4 protein (p.Val61Leu). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.29
BayesDel_addAF
Benign
-0.13
T
BayesDel_noAF
Benign
-0.43
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Benign
0.36
T
Eigen
Benign
-0.031
Eigen_PC
Benign
0.038
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.86
D
M_CAP
Benign
0.053
D
MetaRNN
Uncertain
0.44
T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
1.9
L
PhyloP100
4.7
PrimateAI
Uncertain
0.55
T
PROVEAN
Benign
-1.6
N
REVEL
Benign
0.027
Sift
Benign
0.18
T
Sift4G
Benign
0.41
T
Polyphen
0.32
B
Vest4
0.56
MutPred
0.29
Loss of MoRF binding (P = 0.1026);
MVP
0.60
MPC
0.88
ClinPred
0.94
D
GERP RS
4.3
Varity_R
0.33
gMVP
0.56
Mutation Taster
=79/21
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: rs150451372; hg19: chr20-61990947; API