chr8-27463391-T-C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PP3_ModerateBS2

The NM_000742.4(CHRNA2):c.1052A>G(p.Asn351Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,613,952 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N351T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 8.02

Publications

0 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: Likely_benign. The variant received -2 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.936

BS2

High AC in GnomAd4 at 5 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.1052A>G	p.Asn351Ser	missense	Exon 6 of 7	NP_000733.2	Q15822-1
CHRNA2	NM_001282455.2		c.1007A>G	p.Asn336Ser	missense	Exon 6 of 7	NP_001269384.1	Q15822-2
CHRNA2	NM_001347705.2		c.575A>G	p.Asn192Ser	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.1052A>G	p.Asn351Ser	missense	Exon 6 of 7	ENSP00000385026.1	Q15822-1
CHRNA2	ENST00000523695.5	TSL:1	n.*454A>G		non_coding_transcript_exon	Exon 6 of 7	ENSP00000430612.1	E5RJ54
CHRNA2	ENST00000523695.5	TSL:1	n.*454A>G		3_prime_UTR	Exon 6 of 7	ENSP00000430612.1	E5RJ54

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

151998

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:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

250948

AF XY:

0.00000737

show subpopulations

Gnomad AFR exome

AF:

0.0000616

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.0000995

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:

0.0000137

AC:

AN:

1461836

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

727210

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.0000765

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000464

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53364

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000989

AC:

AN:

1112012

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.495

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:

0.0000329

AC:

AN:

152116

Hom.:

Cov.:

AF XY:

0.0000672

AC XY:

AN XY:

74362

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41488

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5162

South Asian (SAS)

AF:

0.000208

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10594

Middle Eastern (MID)

AF:

0.00340

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

67978

Other (OTH)

AF:

0.000473

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.455

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:

0.0000386

Hom.:

Bravo

AF:

0.0000340

ExAC

AF:

0.0000165

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)

Autosomal dominant nocturnal frontal lobe epilepsy 4 (1)

Inborn genetic diseases (1)

not provided (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.41

BayesDel_addAF

Benign

-0.091

BayesDel_noAF

Benign

-0.19

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.84

Eigen

Pathogenic

0.87

Eigen_PC

Pathogenic

0.78

FATHMM_MKL

Uncertain

0.94

LIST_S2

Uncertain

0.95

M_CAP

Uncertain

0.15

MetaRNN

Pathogenic

0.94

MetaSVM

Uncertain

0.50

MutationAssessor

Pathogenic

4.2

PhyloP100

8.0

PrimateAI

Uncertain

0.69

PROVEAN

Pathogenic

-5.0

REVEL

Pathogenic

0.79

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0010

Polyphen

1.0

Vest4

0.94

MVP

0.93

MPC

0.65

ClinPred

0.99

GERP RS

4.9

Varity_R

0.94

gMVP

0.81

Mutation Taster

=57/43

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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