chr20-63361149-G-A

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_ModerateBP6_Moderate

The NM_000744.7(CHRNA4):c.17C>T(p.Pro6Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000027 in 1,480,514 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 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. P6T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000023 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 0.989

Publications

0 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:

ENSG00000203900 (HGNC:):

ENSG00000203900 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.1760582).

BP6

Variant 20-63361149-G-A is Benign according to our data. Variant chr20-63361149-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 477007.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNA4	NM_000744.7 link	c.17C>T	p.Pro6Leu	missense_variant	Exon 1 of 6	ENST00000370263.9	NP_000735.1	P43681-1B4DK78Q59FV0
CHRNA4	NR_046317.2 link	n.201C>T		non_coding_transcript_exon_variant	Exon 1 of 6
CHRNA4	NM_001256573.2 link	c.-471+28C>T		intron_variant	Intron 1 of 5		NP_001243502.1	P43681Q4VAQ3B4DK78Q59FV0
LOC100130587	NR_110634.1 link	n.183-669G>A		intron_variant	Intron 1 of 4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNA4	ENST00000370263.9 link	c.17C>T	p.Pro6Leu	missense_variant	Exon 1 of 6	1	NM_000744.7	ENSP00000359285.4		P43681-1

Frequencies

GnomAD3 genomes

AF:

0.00000659

AC:

AN:

151752

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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

GnomAD4 exome

AF:

0.00000226

AC:

AN:

1328762

Hom.:

Cov.:

AF XY:

0.00000306

AC XY:

AN XY:

654378

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

26946

American (AMR)

AF:

0.00

AC:

AN:

28826

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

23596

East Asian (EAS)

AF:

0.00

AC:

AN:

29896

South Asian (SAS)

AF:

0.0000136

AC:

AN:

73624

European-Finnish (FIN)

AF:

0.00

AC:

AN:

32656

Middle Eastern (MID)

AF:

0.00

AC:

AN:

3974

European-Non Finnish (NFE)

AF:

0.00000190

AC:

AN:

1054090

Other (OTH)

AF:

0.00

AC:

AN:

55154

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000659

AC:

AN:

151752

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74082

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41364

American (AMR)

AF:

0.0000655

AC:

AN:

15274

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3464

East Asian (EAS)

AF:

0.00

AC:

AN:

5030

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10598

Middle Eastern (MID)

AF:

0.00

AC:

AN:

314

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67896

Other (OTH)

AF:

0.00

AC:

AN:

2080

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000189

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Jan 17, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.083

BayesDel_noAF

Benign

-0.36

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.090

Eigen

Benign

-0.89

Eigen_PC

Benign

-0.91

FATHMM_MKL

Benign

0.068

LIST_S2

Benign

0.50

M_CAP

Pathogenic

0.91

MetaRNN

Benign

0.18

MetaSVM

Benign

-0.84

MutationAssessor

Benign

1.6

PhyloP100

0.99

PrimateAI

Pathogenic

0.80

PROVEAN

Benign

0.40

REVEL

Benign

0.19

Sift

Uncertain

0.019

Sift4G

Benign

0.091

Polyphen

0.0

Vest4

0.098

MutPred

0.30

Loss of relative solvent accessibility (P = 0.0186);

MVP

0.56

MPC

0.40

ClinPred

0.25

GERP RS

1.5

PromoterAI

-0.0019

Neutral

(source)

Varity_R

0.046

gMVP

0.49

Mutation Taster

=94/6

polymorphism

(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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over