8-27463671-C-T

Variant names:

Variant summary

Our verdict is Benign. The variant received -14 ACMG points: 0P and 14B. BP4_ModerateBP6_Very_StrongBS2

The NM_000742.4(CHRNA2):c.772G>A(p.Ala258Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000039 in 1,613,870 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 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. A258D) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.000042 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:2

Conservation

PhyloP100: 2.35

Publications

2 publications found

Variant links:

Genes affected

CHRNA2 (HGNC:1956): (cholinergic receptor nicotinic alpha 2 subunit) Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels formed by a pentameric arrangement of alpha and beta subunits to create distinct muscle and neuronal receptors. Neuronal receptors are found throughout the peripheral and central nervous system where they are involved in fast synaptic transmission. This gene encodes an alpha subunit that is widely expressed in the brain. The proposed structure for nAChR subunits is a conserved N-terminal extracellular domain followed by three conserved transmembrane domains, a variable cytoplasmic loop, a fourth conserved transmembrane domain, and a short C-terminal extracellular region. Mutations in this gene cause autosomal dominant nocturnal frontal lobe epilepsy type 4. Single nucleotide polymorphisms (SNPs) in this gene have been associated with nicotine dependence. [provided by RefSeq, Nov 2009]

CHRNA2 Gene-Disease associations (from GenCC):

autosomal dominant nocturnal frontal lobe epilepsy 4
Inheritance: AD Classification: STRONG, LIMITED Submitted by: G2P, Illumina, Labcorp Genetics (formerly Invitae)
autosomal dominant nocturnal frontal lobe epilepsy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
familial sleep-related hypermotor epilepsy
Inheritance: AD Classification: LIMITED Submitted by: ClinGen
benign familial infantile epilepsy
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
epilepsy
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

CHRNA2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -14 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.06969637).

BP6

Variant 8-27463671-C-T is Benign according to our data. Variant chr8-27463671-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 476995.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS2

High AC in GnomAdExome4 at 62 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000742.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CHRNA2	NM_000742.4	MANE Select	c.772G>A	p.Ala258Thr	missense	Exon 6 of 7	NP_000733.2	Q15822-1
CHRNA2	NM_001282455.2		c.727G>A	p.Ala243Thr	missense	Exon 6 of 7	NP_001269384.1	Q15822-2
CHRNA2	NM_001347705.2		c.295G>A	p.Ala99Thr	missense	Exon 6 of 7	NP_001334634.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CHRNA2	ENST00000407991.3	TSL:5 MANE Select	c.772G>A	p.Ala258Thr	missense	Exon 6 of 7	ENSP00000385026.1	Q15822-1
CHRNA2	ENST00000523695.5	TSL:1	n.*174G>A		non_coding_transcript_exon	Exon 6 of 7	ENSP00000430612.1	E5RJ54
CHRNA2	ENST00000523695.5	TSL:1	n.*174G>A		3_prime_UTR	Exon 6 of 7	ENSP00000430612.1	E5RJ54

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151986

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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

GnomAD2 exomes

AF:

0.000151

AC:

AN:

251452

AF XY:

0.000147

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:

0.000334

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000424

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.0000454

AC XY:

AN XY:

727244

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39696

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000522

AC:

AN:

1112008

Other (OTH)

AF:

0.0000331

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.481

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:

0.00000658

AC:

AN:

151986

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74228

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41372

American (AMR)

AF:

0.00

AC:

AN:

15268

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5172

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10596

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67972

Other (OTH)

AF:

0.00

AC:

AN:

2084

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

Alfa

AF:

0.000119

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.000272

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

ClinVar submissions

Significance:Likely benign

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)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.077

BayesDel_addAF

Benign

-0.40

BayesDel_noAF

Benign

-0.50

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.16

Eigen

Benign

-0.92

Eigen_PC

Benign

-0.76

FATHMM_MKL

Benign

0.66

LIST_S2

Benign

0.73

M_CAP

Benign

0.028

MetaRNN

Benign

0.070

MetaSVM

Benign

-0.95

MutationAssessor

Benign

-1.5

PhyloP100

2.3

PrimateAI

Benign

0.46

PROVEAN

Benign

0.010

REVEL

Benign

0.15

Sift

Benign

0.084

Sift4G

Benign

0.33

Polyphen

0.015

Vest4

0.13

MVP

0.52

MPC

0.18

ClinPred

0.083

GERP RS

1.2

Varity_R

0.10

gMVP

0.41

Mutation Taster

=84/16

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

ClinVar

Computational scores

Splicing

Publications

Other links and lift over