20-63350405-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4

The NM_000744.7(CHRNA4):​c.1006C>A​(p.Arg336Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,576 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R336C) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

5
14

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 2.29
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.3373863).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
CHRNA4NM_000744.7 linkuse as main transcriptc.1006C>A p.Arg336Ser missense_variant 5/6 ENST00000370263.9 NP_000735.1
CHRNA4NM_001256573.2 linkuse as main transcriptc.478C>A p.Arg160Ser missense_variant 5/6 NP_001243502.1
CHRNA4NR_046317.2 linkuse as main transcriptn.1215C>A non_coding_transcript_exon_variant 5/6

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
CHRNA4ENST00000370263.9 linkuse as main transcriptc.1006C>A p.Arg336Ser missense_variant 5/61 NM_000744.7 ENSP00000359285 P1P43681-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000399
AC:
1
AN:
250798
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135826
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461576
Hom.:
0
Cov.:
99
AF XY:
0.00
AC XY:
0
AN XY:
727082
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000270
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
ExAC
AF:
0.00000824
AC:
1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.36
BayesDel_addAF
Benign
-0.0014
T
BayesDel_noAF
Benign
-0.24
CADD
Benign
20
DANN
Benign
0.92
DEOGEN2
Benign
0.20
T;.
Eigen
Benign
-0.24
Eigen_PC
Benign
-0.14
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Benign
0.75
T;T
M_CAP
Uncertain
0.19
D
MetaRNN
Benign
0.34
T;T
MetaSVM
Benign
-0.31
T
MutationAssessor
Benign
1.1
L;.
MutationTaster
Benign
1.0
D
PrimateAI
Uncertain
0.50
T
PROVEAN
Benign
0.87
N;.
REVEL
Uncertain
0.32
Sift
Benign
1.0
T;.
Sift4G
Benign
1.0
T;T
Polyphen
0.063
B;.
Vest4
0.26
MutPred
0.53
Loss of MoRF binding (P = 0.0304);.;
MVP
0.92
MPC
1.2
ClinPred
0.64
D
GERP RS
4.2
Varity_R
0.20
gMVP
0.47

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs56175056; hg19: chr20-61981757; API