20-63349916-C-T

Position:

chr20-63349916-C-T

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_ModerateBP6BS1BS2

The NM_000744.7(CHRNA4):c.1495G>A(p.Ala499Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000345 in 1,593,490 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 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 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 0.391

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 -11 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.088729024).

BP6

Variant 20-63349916-C-T is Benign according to our data. Variant chr20-63349916-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 287521.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=3}.

BS1

Variant frequency is greater than expected in population mid. gnomad4_exome allele frequency = 0.0000375 (54/1441282) while in subpopulation MID AF= 0.000358 (2/5592). AF 95% confidence interval is 0.0000627. There are 0 homozygotes in gnomad4_exome. There are 19 alleles in male gnomad4_exome subpopulation. Median coverage is 83. This position pass quality control queck.

BS2

High AC in GnomAdExome4 at 54 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
CHRNA4	NM_000744.7 linkuse as main transcript	c.1495G>A	p.Ala499Thr	missense_variant	5/6	ENST00000370263.9	NP_000735.1
CHRNA4	NM_001256573.2 linkuse as main transcript	c.967G>A	p.Ala323Thr	missense_variant	5/6		NP_001243502.1
CHRNA4	NR_046317.2 linkuse as main transcript	n.1704G>A		non_coding_transcript_exon_variant	5/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHRNA4	ENST00000370263.9 linkuse as main transcript	c.1495G>A	p.Ala499Thr	missense_variant	5/6	1	NM_000744.7	ENSP00000359285	P1	P43681-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152208

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000270

AC:

AN:

222402

Hom.:

AF XY:

0.0000247

AC XY:

AN XY:

121296

show subpopulations

Gnomad AFR exome

AF:

0.000145

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000708

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000202

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000375

AC:

AN:

1441282

Hom.:

Cov.:

AF XY:

0.0000266

AC XY:

AN XY:

714360

show subpopulations

Gnomad4 AFR exome

AF:

0.0000302

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000356

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000409

Gnomad4 OTH exome

AF:

0.0000506

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74354

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000112

Hom.:

Bravo

AF:

0.0000378

ESP6500AA

AF:

0.000458

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00000833

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 13, 2019	Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Apr 19, 2016	- -

Autosomal dominant nocturnal frontal lobe epilepsy 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Feb 01, 2018

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 28, 2023

- -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 26, 2022

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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.069

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Benign

-0.47

CADD

Benign

5.8

DANN

Benign

0.90

DEOGEN2

Benign

0.29

T;.

Eigen

Benign

-1.8

Eigen_PC

Benign

-2.0

FATHMM_MKL

Benign

0.076

LIST_S2

Benign

0.49

T;T

M_CAP

Uncertain

0.15

MetaRNN

Benign

0.089

T;T

MetaSVM

Benign

-0.77

MutationAssessor

Uncertain

2.2

M;.

MutationTaster

Benign

1.0

PrimateAI

Benign

0.40

PROVEAN

Benign

-0.20

N;.

REVEL

Benign

0.26

Sift

Benign

0.16

T;.

Sift4G

Benign

0.41

T;T

Polyphen

0.86

P;.

Vest4

0.049

MVP

0.44

MPC

0.39

ClinPred

0.24

GERP RS

-4.3

Varity_R

0.054

gMVP

0.23

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