rs758895760

Variant summary

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

The NM_000744.7(CHRNA4):​c.1609C>T​(p.Pro537Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000151 in 1,453,614 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: not found (cov: 33)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

1
18

Clinical Significance

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

Conservation

PhyloP100: 1.83

Publications

2 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: Benign. The variant received -7 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.106532186).
BP6
Variant 20-63349802-G-A is Benign according to our data. Variant chr20-63349802-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 393180.
BS2
High AC in GnomAdExome4 at 22 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHRNA4NM_000744.7 linkc.1609C>T p.Pro537Ser missense_variant Exon 5 of 6 ENST00000370263.9 NP_000735.1 P43681-1B4DK78Q59FV0
CHRNA4NM_001256573.2 linkc.1081C>T p.Pro361Ser missense_variant Exon 5 of 6 NP_001243502.1 P43681Q4VAQ3B4DK78Q59FV0
CHRNA4NR_046317.2 linkn.1818C>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.1609C>T p.Pro537Ser missense_variant Exon 5 of 6 1 NM_000744.7 ENSP00000359285.4 P43681-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.0000649
AC:
16
AN:
246464
AF XY:
0.0000299
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000466
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:
0.0000151
AC:
22
AN:
1453614
Hom.:
0
Cov.:
83
AF XY:
0.00000831
AC XY:
6
AN XY:
721590
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33270
American (AMR)
AF:
0.000450
AC:
20
AN:
44478
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25962
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39464
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86018
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52098
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5748
European-Non Finnish (NFE)
AF:
0.00000181
AC:
2
AN:
1106624
Other (OTH)
AF:
0.00
AC:
0
AN:
59952
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.498
Heterozygous variant carriers
0
2
4
7
9
11
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
Cov.:
33
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.0000165
AC:
2

ClinVar

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

Submissions by phenotype

not provided Uncertain:1
Jan 23, 2017
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

A variant of uncertain significance has been identified in the CHRNA4 gene. The P537S variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The P537S variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The P537S variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. However, this substitution occurs at a position that is not conserved and in silico analysis predicts this variant likely does not alter the protein structure/function. Additionally, this amino acid substitution is not predicted to occur within the transmembrane region of the protein, where the vast majority of pathogenic missense variants have been identified in association with epilepsy (Steinlein et al., 2010). Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Autosomal dominant nocturnal frontal lobe epilepsy Benign:1
Oct 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
0.074
BayesDel_addAF
Benign
-0.30
T
BayesDel_noAF
Benign
-0.35
CADD
Benign
14
DANN
Benign
0.91
DEOGEN2
Benign
0.32
T;.
Eigen
Benign
-0.67
Eigen_PC
Benign
-0.67
FATHMM_MKL
Benign
0.16
N
LIST_S2
Benign
0.71
T;T
M_CAP
Uncertain
0.16
D
MetaRNN
Benign
0.11
T;T
MetaSVM
Benign
-0.85
T
MutationAssessor
Benign
1.4
L;.
PhyloP100
1.8
PrimateAI
Benign
0.33
T
PROVEAN
Benign
-0.70
N;.
REVEL
Benign
0.15
Sift
Benign
0.14
T;.
Sift4G
Benign
0.54
T;T
Polyphen
0.27
B;.
Vest4
0.18
MutPred
0.31
Gain of phosphorylation at P537 (P = 0.0184);.;
MVP
0.82
MPC
0.72
ClinPred
0.036
T
GERP RS
2.5
Varity_R
0.037
gMVP
0.27
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: rs758895760; hg19: chr20-61981154; API