chr20-63350146-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000744.7(CHRNA4):c.1265G>A(p.Cys422Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000254 in 1,572,206 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. C422C) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2O:1

Conservation

PhyloP100: 2.41

Publications

1 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: G2P, Labcorp Genetics (formerly Invitae)
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: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000744.7. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CHRNA4	NM_000744.7	MANE Select	c.1265G>A	p.Cys422Tyr	missense	Exon 5 of 6	NP_000735.1	P43681-1
CHRNA4	NM_001256573.2		c.737G>A	p.Cys246Tyr	missense	Exon 5 of 6	NP_001243502.1	Q4VAQ3
CHRNA4	NR_046317.2		n.1474G>A		non_coding_transcript_exon	Exon 5 of 6

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CHRNA4	ENST00000370263.9	TSL:1 MANE Select	c.1265G>A	p.Cys422Tyr	missense	Exon 5 of 6	ENSP00000359285.4	P43681-1
CHRNA4	ENST00000463705.5	TSL:1	n.1913G>A		non_coding_transcript_exon	Exon 4 of 5
CHRNA4	ENST00000467563.3	TSL:1	n.1335G>A		non_coding_transcript_exon	Exon 5 of 6

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152148

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

GnomAD2 exomes

AF:

0.00

AC:

AN:

197020

AF XY:

0.00

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000211

AC:

AN:

1420058

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

700914

show subpopulations

African (AFR)

AF:

0.0000305

AC:

AN:

32740

American (AMR)

AF:

0.00

AC:

AN:

40048

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

24776

East Asian (EAS)

AF:

0.00

AC:

AN:

38178

South Asian (SAS)

AF:

0.00

AC:

AN:

81606

European-Finnish (FIN)

AF:

0.00

AC:

AN:

49938

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5652

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1088516

Other (OTH)

AF:

0.0000341

AC:

AN:

58604

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

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:

0.00000657

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74328

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41432

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5184

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68016

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.0000167

AC:

ClinVar

ClinVar submissions

Significance:Uncertain significance

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Autosomal dominant nocturnal frontal lobe epilepsy (1)

Inborn genetic diseases (1)

Tobacco use disorder (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.086

BayesDel_addAF

Uncertain

0.013

BayesDel_noAF

Benign

-0.22

CADD

Benign

(source)

DANN

Benign

0.72

DEOGEN2

Uncertain

0.54

Eigen

Benign

-0.40

Eigen_PC

Benign

-0.47

FATHMM_MKL

Uncertain

0.84

LIST_S2

Benign

0.71

M_CAP

Uncertain

0.19

MetaRNN

Uncertain

0.46

MetaSVM

Benign

-0.58

MutationAssessor

Pathogenic

3.0

PhyloP100

2.4

PrimateAI

Uncertain

0.50

PROVEAN

Benign

-1.9

REVEL

Uncertain

0.31

Sift

Benign

0.63

Sift4G

Benign

0.51

Polyphen

0.49

Vest4

0.45

MutPred

0.32

Gain of phosphorylation at C422 (P = 0.0021)

MVP

0.76

MPC

0.97

ClinPred

0.91

GERP RS

3.6

Varity_R

0.20

gMVP

0.37

Mutation Taster

=65/35

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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over