rs549863396

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_000744.7(CHRNA4):c.1484G>C(p.Arg495Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000201 in 1,591,366 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 Likely benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R495Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: -0.122

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 Benign. Variant got -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.06687701).

BP6

Variant 20-63349927-C-G is Benign according to our data. Variant chr20-63349927-C-G is described in ClinVar as [Likely_benign]. Clinvar id is 419330.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.0000263 (4/152322) while in subpopulation EAS AF= 0.000773 (4/5174). AF 95% confidence interval is 0.000263. There are 0 homozygotes in gnomad4. There are 3 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High AC in GnomAdExome at 16 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
CHRNA4	NM_000744.7 linkuse as main transcript	c.1484G>C	p.Arg495Pro	missense_variant	5/6	ENST00000370263.9
CHRNA4	NM_001256573.2 linkuse as main transcript	c.956G>C	p.Arg319Pro	missense_variant	5/6
CHRNA4	NR_046317.2 linkuse as main transcript	n.1693G>C		non_coding_transcript_exon_variant	5/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNA4	ENST00000370263.9 linkuse as main transcript	c.1484G>C	p.Arg495Pro	missense_variant	5/6	1	NM_000744.7	P1	P43681-1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152204

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000771

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000739

AC:

AN:

216450

Hom.:

AF XY:

0.0000339

AC XY:

AN XY:

117912

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000851

Gnomad SAS exome

AF:

0.0000362

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000104

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000195

AC:

AN:

1439044

Hom.:

Cov.:

AF XY:

0.0000182

AC XY:

AN XY:

713084

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000514

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000273

Gnomad4 OTH exome

AF:

0.0000844

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152322

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74482

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000773

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000227

ExAC

AF:

0.0000500

AC:

ClinVar

Significance: Likely benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Oct 07, 2023

- -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 05, 2024

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

not provided

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Jun 19, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

BayesDel_addAF

Benign

-0.39

BayesDel_noAF

Benign

-0.41

Cadd

Benign

Dann

Benign

0.94

DEOGEN2

Benign

0.25

T;.

Eigen

Benign

-0.81

Eigen_PC

Benign

-0.99

FATHMM_MKL

Benign

0.095

LIST_S2

Benign

0.65

T;T

M_CAP

Uncertain

0.092

MetaRNN

Benign

0.067

T;T

MetaSVM

Benign

-0.79

MutationAssessor

Benign

0.97

L;.

MutationTaster

Benign

1.0

PrimateAI

Benign

0.36

PROVEAN

Benign

-0.39

N;.

REVEL

Benign

0.24

Sift

Benign

0.056

T;.

Sift4G

Benign

0.25

T;T

Polyphen

0.74

P;.

Vest4

0.18

MutPred

0.56

Gain of catalytic residue at P494 (P = 0.0112);.;

MVP

0.85

MPC

0.59

ClinPred

0.089

GERP RS

-3.9

Varity_R

0.21

gMVP

0.33

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