20-63346761-G-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP6BS2

The NM_000744.7(CHRNA4):c.1861C>A(p.Pro621Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000242 in 1,611,284 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P621S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000098 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 6.55

Publications

2 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 -5 ACMG points.

BP6

Variant 20-63346761-G-T is Benign according to our data. Variant chr20-63346761-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 205041.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=2}.

BS2

High AC in GnomAd4 at 15 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNA4	NM_000744.7 link	c.1861C>A	p.Pro621Thr	missense_variant	Exon 6 of 6	ENST00000370263.9	NP_000735.1	P43681-1B4DK78Q59FV0
CHRNA4	NM_001256573.2 link	c.1333C>A	p.Pro445Thr	missense_variant	Exon 6 of 6		NP_001243502.1	P43681Q4VAQ3B4DK78Q59FV0
CHRNA4	NR_046317.2 link	n.2070C>A		non_coding_transcript_exon_variant	Exon 6 of 6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNA4	ENST00000370263.9 link	c.1861C>A	p.Pro621Thr	missense_variant	Exon 6 of 6	1	NM_000744.7	ENSP00000359285.4		P43681-1

Frequencies

GnomAD3 genomes

AF:

0.0000985

AC:

AN:

152220

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000916

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

GnomAD2 exomes

AF:

0.0000244

AC:

AN:

245578

AF XY:

0.00000748

show subpopulations

Gnomad AFR exome

AF:

0.0000625

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000911

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000165

AC:

AN:

1458946

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

725890

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33452

American (AMR)

AF:

0.000201

AC:

AN:

44690

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26114

East Asian (EAS)

AF:

0.00

AC:

AN:

39690

South Asian (SAS)

AF:

0.00

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

51034

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

0.00000990

AC:

AN:

1111636

Other (OTH)

AF:

0.0000663

AC:

AN:

60320

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.469

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.0000985

AC:

AN:

152338

Hom.:

Cov.:

AF XY:

0.000134

AC XY:

AN XY:

74492

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41586

American (AMR)

AF:

0.000915

AC:

AN:

15308

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5178

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68026

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.448

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.000234

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy 1

Uncertain:1

May 24, 2021

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Nov 25, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Benign:1

Sep 22, 2020

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.55

BayesDel_addAF

Pathogenic

0.20

BayesDel_noAF

Pathogenic

0.24

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.63

D;.

Eigen

Pathogenic

0.80

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

D;D

M_CAP

Pathogenic

0.44

MetaRNN

Uncertain

0.74

D;D

MetaSVM

Uncertain

0.33

MutationAssessor

Uncertain

2.8

M;.

PhyloP100

6.5

PrimateAI

Uncertain

0.71

PROVEAN

Pathogenic

-5.5

D;.

REVEL

Pathogenic

0.72

Sift

Pathogenic

0.0

D;.

Sift4G

Pathogenic

0.0010

D;D

Polyphen

1.0

D;.

Vest4

0.78

MVP

0.88

MPC

1.3

ClinPred

0.98

GERP RS

4.4

Varity_R

0.82

gMVP

0.89

Mutation Taster

=28/72

disease causing

(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

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20-63346761-G-T

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