20-63356000-G-A

Position:

chr20-63356000-G-A

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 4P and 9B. PP3_StrongBP6BS1BS2

The ENST00000370263.9(CHRNA4):c.358C>T(p.Arg120Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000714 in 1,611,702 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. R120R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 30)

Exomes 𝑓: 0.000073 ( 0 hom. )

Consequence

CHRNA4
ENST00000370263.9 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 0.550

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 -5 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.942

BP6

Variant 20-63356000-G-A is Benign according to our data. Variant chr20-63356000-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 205046.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=2, Likely_benign=1}.

BS1

Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.0000529 (8/151178) while in subpopulation NFE AF= 0.000103 (7/67814). AF 95% confidence interval is 0.0000478. There are 0 homozygotes in gnomad4. There are 4 alleles in male gnomad4 subpopulation. Median coverage is 30. This position pass quality control queck.

BS2

High AC in GnomAd4 at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
CHRNA4	NM_000744.7 linkuse as main transcript	c.358C>T	p.Arg120Trp	missense_variant	4/6	ENST00000370263.9	NP_000735.1
CHRNA4	NM_001256573.2 linkuse as main transcript	c.-189C>T		5_prime_UTR_variant	4/6		NP_001243502.1
CHRNA4	NR_046317.2 linkuse as main transcript	n.567C>T		non_coding_transcript_exon_variant	4/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHRNA4	ENST00000370263.9 linkuse as main transcript	c.358C>T	p.Arg120Trp	missense_variant	4/6	1	NM_000744.7	ENSP00000359285	P1	P43681-1

Frequencies

GnomAD3 genomes

AF:

0.0000529

AC:

AN:

151178

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000244

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:

0.000103

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000640

AC:

AN:

249822

Hom.:

AF XY:

0.0000885

AC XY:

AN XY:

135592

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:

0.000163

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000977

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000733

AC:

107

AN:

1460524

Hom.:

Cov.:

AF XY:

0.0000702

AC XY:

AN XY:

726578

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000928

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000872

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000529

AC:

AN:

151178

Hom.:

Cov.:

AF XY:

0.0000542

AC XY:

AN XY:

73772

show subpopulations

Gnomad4 AFR

AF:

0.0000244

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:

0.000103

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000579

Hom.:

Bravo

AF:

0.0000302

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000662

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy 1;C1861063:Tobacco addiction, susceptibility to

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Feb 20, 2020

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 24, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.30

BayesDel_addAF

Benign

-0.032

BayesDel_noAF

Uncertain

-0.020

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.76

Eigen

Uncertain

0.22

Eigen_PC

Benign

0.031

FATHMM_MKL

Benign

0.70

LIST_S2

Uncertain

0.97

M_CAP

Pathogenic

0.62

MetaRNN

Pathogenic

0.94

MetaSVM

Uncertain

0.19

MutationTaster

Benign

1.0

PrimateAI

Pathogenic

0.83

PROVEAN

Uncertain

-3.4

REVEL

Pathogenic

0.66

Sift

Uncertain

0.011

Sift4G

Uncertain

0.020

Polyphen

1.0

Vest4

0.85

MVP

0.84

MPC

1.2

ClinPred

0.93

GERP RS

-2.6

Varity_R

0.17

gMVP

0.83

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