rs1317529556

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4

The NM_000744.7(CHRNA4):c.1412T>C(p.Met471Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000388 in 1,545,724 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M471V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000022 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.54

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

CHRNA4 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.28715244).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein
CHRNA4	NM_000744.7 link	c.1412T>C	p.Met471Thr	missense_variant	Exon 5 of 6	ENST00000370263.9	NP_000735.1
CHRNA4	NM_001256573.2 link	c.884T>C	p.Met295Thr	missense_variant	Exon 5 of 6		NP_001243502.1
CHRNA4	NR_046317.2 link	n.1621T>C		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.1412T>C	p.Met471Thr	missense_variant	Exon 5 of 6	1	NM_000744.7	ENSP00000359285.4

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152150

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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

GnomAD2 exomes

AF:

0.00000626

AC:

AN:

159852

AF XY:

0.0000116

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000147

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000215

AC:

AN:

1393574

Hom.:

Cov.:

AF XY:

0.00000291

AC XY:

AN XY:

686262

show subpopulations

African (AFR)

AF:

0.0000625

AC:

AN:

32010

American (AMR)

AF:

0.00

AC:

AN:

36168

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

23528

East Asian (EAS)

AF:

0.00

AC:

AN:

37366

South Asian (SAS)

AF:

0.00

AC:

AN:

77082

European-Finnish (FIN)

AF:

0.00

AC:

AN:

47462

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5452

European-Non Finnish (NFE)

AF:

9.28e-7

AC:

AN:

1077006

Other (OTH)

AF:

0.00

AC:

AN:

57500

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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

AF:

0.0000197

AC:

AN:

152150

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74322

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41442

American (AMR)

AF:

0.00

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5188

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

67994

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy 1

Uncertain:1

Sep 22, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Autosomal dominant nocturnal frontal lobe epilepsy

Uncertain:1

Sep 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 471 of the CHRNA4 protein (p.Met471Thr). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 477001). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant¬†is likely to be tolerated. 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. -

Inborn genetic diseases

Uncertain:1

Dec 17, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.1412T>C (p.M471T) alteration is located in exon 5 (coding exon 5) of the CHRNA4 gene. This alteration results from a T to C substitution at nucleotide position 1412, causing the methionine (M) at amino acid position 471 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.086

BayesDel_addAF

Benign

-0.036

BayesDel_noAF

Benign

-0.29

CADD

Benign

(source)

DANN

Benign

0.33

DEOGEN2

Benign

0.33

T;.

Eigen

Benign

-0.35

Eigen_PC

Benign

-0.36

FATHMM_MKL

Uncertain

0.94

LIST_S2

Benign

0.56

T;T

M_CAP

Uncertain

0.085

MetaRNN

Benign

0.29

T;T

MetaSVM

Benign

-0.71

MutationAssessor

Benign

1.4

L;.

PhyloP100

3.5

PrimateAI

Benign

0.44

PROVEAN

Benign

-0.98

N;.

REVEL

Benign

0.26

Sift

Benign

0.19

T;.

Sift4G

Benign

0.50

T;T

Polyphen

0.18

B;.

Vest4

0.32

MutPred

0.36

Gain of glycosylation at M471 (P = 0.0038);.;

MVP

0.80

MPC

0.52

ClinPred

0.19

GERP RS

3.9

Varity_R

0.14

gMVP

0.39

Mutation Taster

=82/18

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over