rs142137599

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The NM_000744.7(CHRNA4):c.1525G>A(p.Ala509Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000138 in 1,592,274 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 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: 𝑓 0.000053 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000097 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 0.501

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0933274).

BS2

High AC in GnomAd4 at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNA4	NM_000744.7 link	c.1525G>A	p.Ala509Thr	missense_variant	Exon 5 of 6	ENST00000370263.9	NP_000735.1	P43681-1B4DK78Q59FV0
CHRNA4	NM_001256573.2 link	c.997G>A	p.Ala333Thr	missense_variant	Exon 5 of 6		NP_001243502.1	P43681Q4VAQ3B4DK78Q59FV0
CHRNA4	NR_046317.2 link	n.1734G>A		non_coding_transcript_exon_variant	Exon 5 of 6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNA4	ENST00000370263.9 link	c.1525G>A	p.Ala509Thr	missense_variant	Exon 5 of 6	1	NM_000744.7	ENSP00000359285.4		P43681-1

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152136

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000882

AC:

AN:

226874

Hom.:

AF XY:

0.00000810

AC XY:

AN XY:

123526

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:

0.0000198

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000972

AC:

AN:

1440138

Hom.:

Cov.:

AF XY:

0.0000140

AC XY:

AN XY:

713272

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:

0.0000118

Gnomad4 OTH exome

AF:

0.0000169

GnomAD4 genome

AF:

0.0000526

AC:

AN:

152136

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74308

show subpopulations

Gnomad4 AFR

AF:

0.000145

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000573

Hom.:

Bravo

AF:

0.0000642

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000117

AC:

ExAC

AF:

0.00000832

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Oct 14, 2013

Genetic Services Laboratory, University of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 05, 2018

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 A509T variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The A509T variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). The A509T 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 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). In-silico analyses, including protein predictors and evolutionary conservation, support that this variant does not alter protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Inborn genetic diseases

Uncertain:1

Jul 07, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The alteration results in an amino acid change:_x000D_ _x000D_ The c.1525G>A (p.A509T) alteration is located in coding exon 5 of the CHRNA4 gene. This alteration results from a G to A substitution at nucleotide position 1525, causing the alanine (A) at amino acid position 509 to be replaced by a threonine (T). The alteration is rare in population databases: _x000D_ _x000D_ Based on data from the Genome Aggregation Database (gnomAD), the c.1525G>A alteration was observed in 0.0012% (3/258226) of total alleles studied. The altered amino acid is not conserved throughout evolution:_x000D_ _x000D_ The p.A509 amino acid is not conserved in available vertebrate species. The alteration is predicted tolerated by in silico modeling:_x000D_ _x000D_ The p.A509T alteration is predicted to be tolerated by in silico analysis. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Jan 22, 2025

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

0.066

BayesDel_addAF

Benign

-0.17

BayesDel_noAF

Benign

-0.48

CADD

Benign

7.7

DANN

Benign

0.97

DEOGEN2

Benign

0.21

T;.

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.66

LIST_S2

Benign

0.64

T;T

M_CAP

Uncertain

0.11

MetaRNN

Benign

0.093

T;T

MetaSVM

Benign

-0.92

MutationAssessor

Benign

1.2

L;.

PrimateAI

Benign

0.38

PROVEAN

Benign

-0.040

N;.

REVEL

Benign

0.085

Sift

Benign

0.33

T;.

Sift4G

Benign

0.33

T;T

Polyphen

0.0060

B;.

Vest4

0.14

MVP

0.63

MPC

0.52

ClinPred

0.15

GERP RS

1.0

Varity_R

0.021

gMVP

0.31

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over