20-63350918-C-T
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Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2
The NM_000744.7(CHRNA4):c.493G>A(p.Val165Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,752 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).
Frequency
Genomes: not found (cov: 31)
Exomes 𝑓: 0.0000021 ( 0 hom. )
Consequence
CHRNA4
NM_000744.7 missense
NM_000744.7 missense
Scores
1
10
8
Clinical Significance
Conservation
PhyloP100: 7.74
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]
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ACMG classification
Classification made for transcript
Verdict is Uncertain_significance. Variant got 2 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
CHRNA4 | NM_000744.7 | c.493G>A | p.Val165Ile | missense_variant | 5/6 | ENST00000370263.9 | |
CHRNA4 | NM_001256573.2 | c.-36G>A | 5_prime_UTR_variant | 5/6 | |||
CHRNA4 | NR_046317.2 | n.702G>A | non_coding_transcript_exon_variant | 5/6 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
CHRNA4 | ENST00000370263.9 | c.493G>A | p.Val165Ile | missense_variant | 5/6 | 1 | NM_000744.7 | P1 |
Frequencies
GnomAD3 genomes Cov.: 31
GnomAD3 genomes
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31
GnomAD3 exomes AF: 0.00000796 AC: 2AN: 251170Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135882
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GnomAD4 exome AF: 0.00000205 AC: 3AN: 1461752Hom.: 0 Cov.: 40 AF XY: 0.00000275 AC XY: 2AN XY: 727152
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GnomAD4 genome Cov.: 31
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31
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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
Uncertain significance, criteria provided, single submitter | clinical testing | Invitae | Aug 30, 2023 | This variant is present in population databases (rs762764855, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with CHRNA4-related conditions. ClinVar contains an entry for this variant (Variation ID: 411849). 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) performed at Invitae indicates that this missense variant is not expected to disrupt CHRNA4 protein function. 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. This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 165 of the CHRNA4 protein (p.Val165Ile). - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
BayesDel_addAF
Benign
T
BayesDel_noAF
Uncertain
CADD
Pathogenic
DANN
Uncertain
DEOGEN2
Benign
T;.
Eigen
Uncertain
Eigen_PC
Uncertain
FATHMM_MKL
Uncertain
D
LIST_S2
Uncertain
D;D
M_CAP
Uncertain
D
MetaRNN
Uncertain
T;T
MetaSVM
Uncertain
D
MutationAssessor
Benign
L;.
MutationTaster
Benign
D
PrimateAI
Pathogenic
D
PROVEAN
Benign
N;.
REVEL
Uncertain
Sift
Benign
T;.
Sift4G
Benign
T;T
Polyphen
D;.
Vest4
MutPred
Loss of loop (P = 0.2237);.;
MVP
MPC
ClinPred
D
GERP RS
Varity_R
gMVP
Splicing
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Calibrated prediction
Score
Prediction
SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at