chr20-63350447-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_ModerateBP6_ModerateBS2

The NM_000744.7(CHRNA4):c.964G>A(p.Val322Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000103 in 1,461,664 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

CHRNA4
NM_000744.7 missense

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 0.203

Publications

3 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: Benign. The variant received -8 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.11671239).

BP6

Variant 20-63350447-C-T is Benign according to our data. Variant chr20-63350447-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 477011.Status of the report is criteria_provided_single_submitter, 1 stars.

BS2

High AC in GnomAdExome4 at 15 AD gene.

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
CHRNA4	NM_000744.7	MANE Select	c.964G>A	p.Val322Ile	missense	Exon 5 of 6	NP_000735.1
CHRNA4	NM_001256573.2		c.436G>A	p.Val146Ile	missense	Exon 5 of 6	NP_001243502.1
CHRNA4	NR_046317.2		n.1173G>A		non_coding_transcript_exon	Exon 5 of 6

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
CHRNA4	ENST00000370263.9	TSL:1 MANE Select	c.964G>A	p.Val322Ile	missense	Exon 5 of 6	ENSP00000359285.4
CHRNA4	ENST00000463705.5	TSL:1	n.1612G>A		non_coding_transcript_exon	Exon 4 of 5
CHRNA4	ENST00000467563.3	TSL:1	n.1034G>A		non_coding_transcript_exon	Exon 5 of 6

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000199

AC:

AN:

250914

AF XY:

0.0000147

show subpopulations

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:

0.0000103

AC:

AN:

1461664

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727122

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000464

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53198

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000989

AC:

AN:

1112008

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.488

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

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000247

AC:

ClinVar

ClinVar submissions as Germline

Significance:Likely benign

Revision:criteria provided, single submitter

View on ClinVar

Pathogenic

VUS

Benign

Condition

Autosomal dominant nocturnal frontal lobe epilepsy (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.065

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.37

CADD

Benign

(source)

DANN

Benign

0.93

DEOGEN2

Benign

0.25

Eigen

Benign

-0.56

Eigen_PC

Benign

-0.45

FATHMM_MKL

Benign

0.43

LIST_S2

Benign

0.85

M_CAP

Benign

0.034

MetaRNN

Benign

0.12

MetaSVM

Benign

-0.71

MutationAssessor

Benign

0.35

PhyloP100

0.20

PrimateAI

Benign

0.45

PROVEAN

Benign

-0.53

REVEL

Benign

0.21

Sift

Benign

0.25

Sift4G

Benign

0.30

Polyphen

0.010

Vest4

0.11

MutPred

0.57

Loss of catalytic residue at V322 (P = 0.018)

MVP

0.73

MPC

0.32

ClinPred

0.13

GERP RS

-1.1

Varity_R

0.044

gMVP

0.19

Mutation Taster

=80/20

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over