20-63349777-G-A

Position:

chr20-63349777-G-A

Variant summary

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

The NM_000744.7(CHRNA4):c.1634C>T(p.Thr545Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000064 in 1,610,432 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 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 0.000013 ( 0 hom., cov: 34)

Exomes 𝑓: 0.000069 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1B:4O:1

Conservation

PhyloP100: 0.419

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=0.1337341).

BP6

Variant 20-63349777-G-A is Benign according to our data. Variant chr20-63349777-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 98320.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, not_provided=1, Uncertain_significance=1}.

BS1

Variant frequency is greater than expected in population mid. gnomad4_exome allele frequency = 0.0000693 (101/1458186) while in subpopulation MID AF= 0.000174 (1/5760). AF 95% confidence interval is 0.0000607. There are 0 homozygotes in gnomad4_exome. There are 43 alleles in male gnomad4_exome subpopulation. Median coverage is 74. This position pass quality control queck.

BS2

High AC in GnomAdExome4 at 101 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
CHRNA4	NM_000744.7 linkuse as main transcript	c.1634C>T	p.Thr545Met	missense_variant	5/6	ENST00000370263.9	NP_000735.1
CHRNA4	NM_001256573.2 linkuse as main transcript	c.1106C>T	p.Thr369Met	missense_variant	5/6		NP_001243502.1
CHRNA4	NR_046317.2 linkuse as main transcript	n.1843C>T		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.1634C>T	p.Thr545Met	missense_variant	5/6	1	NM_000744.7	ENSP00000359285	P1	P43681-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152246

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000606

AC:

AN:

247718

Hom.:

AF XY:

0.0000817

AC XY:

AN XY:

134596

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000145

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:

0.0000810

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.0000693

AC:

101

AN:

1458186

Hom.:

Cov.:

AF XY:

0.0000593

AC XY:

AN XY:

724922

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000135

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000697

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000739

Gnomad4 OTH exome

AF:

0.0000996

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152246

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74376

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000422

Hom.:

Bravo

AF:

0.0000264

ExAC

AF:

0.0000744

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.000109

EpiControl

AF:

0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:1Benign:4Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:2

Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2022	CHRNA4: BP4 -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	May 06, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 28, 2015	- -

Frontotemporal dementia

Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

Guerreiro-Bras Laboratory, Van Andel Institute

Feb 02, 2022

- -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 22, 2023

- -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 19, 2021

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. -

Tobacco use disorder

Other:1

not provided, no classification provided

literature only

Psychiatry Genetics Yale University

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.079

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.37

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.30

T;.

Eigen

Benign

-0.86

Eigen_PC

Benign

-1.0

FATHMM_MKL

Benign

0.065

LIST_S2

Benign

0.48

T;T

M_CAP

Uncertain

0.14

MetaRNN

Benign

0.13

T;T

MetaSVM

Benign

-0.61

MutationAssessor

Benign

0.28

N;.

MutationTaster

Benign

1.0

PrimateAI

Benign

0.37

PROVEAN

Benign

-0.030

N;.

REVEL

Uncertain

0.33

Sift

Benign

0.12

T;.

Sift4G

Benign

0.11

T;T

Polyphen

0.86

P;.

Vest4

0.12

MutPred

0.41

Loss of glycosylation at T545 (P = 0.003);.;

MVP

0.93

MPC

0.46

ClinPred

0.056

GERP RS

-3.4

Varity_R

0.023

gMVP

0.37

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