rs773450609

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_ModerateBP6_Moderate

The NM_000744.7(CHRNA4):​c.1420C>T​(p.Pro474Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000129 in 1,550,282 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P474R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 34)
Exomes 𝑓: 7.2e-7 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

1
18

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 0.248

Publications

0 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: Likely_benign. The variant received -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.108534604).
BP6
Variant 20-63349991-G-A is Benign according to our data. Variant chr20-63349991-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 204999.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA4NM_000744.7 linkc.1420C>T p.Pro474Ser missense_variant Exon 5 of 6 ENST00000370263.9 NP_000735.1 P43681-1B4DK78Q59FV0
CHRNA4NM_001256573.2 linkc.892C>T p.Pro298Ser missense_variant Exon 5 of 6 NP_001243502.1 P43681Q4VAQ3B4DK78Q59FV0
CHRNA4NR_046317.2 linkn.1629C>T non_coding_transcript_exon_variant Exon 5 of 6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHRNA4ENST00000370263.9 linkc.1420C>T p.Pro474Ser missense_variant Exon 5 of 6 1 NM_000744.7 ENSP00000359285.4 P43681-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152258
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.00000609
AC:
1
AN:
164110
AF XY:
0.0000113
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000393
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:
7.15e-7
AC:
1
AN:
1398024
Hom.:
0
Cov.:
83
AF XY:
0.00000145
AC XY:
1
AN XY:
688922
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32148
American (AMR)
AF:
0.0000273
AC:
1
AN:
36694
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
23902
East Asian (EAS)
AF:
0.00
AC:
0
AN:
37352
South Asian (SAS)
AF:
0.00
AC:
0
AN:
78100
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
47660
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5466
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1079026
Other (OTH)
AF:
0.00
AC:
0
AN:
57676
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152258
Hom.:
0
Cov.:
34
AF XY:
0.00
AC XY:
0
AN XY:
74382
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41474
American (AMR)
AF:
0.0000654
AC:
1
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
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:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
ExAC
AF:
0.0000169
AC:
2

ClinVar

Significance: Likely benign
Submissions summary: Benign:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy Benign:1
Dec 23, 2023
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
0.072
BayesDel_addAF
Benign
-0.14
T
BayesDel_noAF
Benign
-0.44
CADD
Benign
12
DANN
Benign
0.57
DEOGEN2
Benign
0.25
T;.
Eigen
Benign
-0.70
Eigen_PC
Benign
-0.64
FATHMM_MKL
Uncertain
0.78
D
LIST_S2
Benign
0.60
T;T
M_CAP
Benign
0.049
D
MetaRNN
Benign
0.11
T;T
MetaSVM
Benign
-0.95
T
MutationAssessor
Benign
0.90
L;.
PhyloP100
0.25
PrimateAI
Benign
0.32
T
PROVEAN
Benign
0.52
N;.
REVEL
Benign
0.098
Sift
Benign
0.37
T;.
Sift4G
Benign
0.87
T;T
Polyphen
0.0050
B;.
Vest4
0.12
MutPred
0.35
Loss of relative solvent accessibility (P = 0.0071);.;
MVP
0.88
MPC
0.43
ClinPred
0.042
T
GERP RS
2.6
Varity_R
0.020
gMVP
0.28
Mutation Taster
=99/1
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: rs773450609; hg19: chr20-61981343; API