rs74341575

Positions:

chr8-27463370-C-A

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4BP6BS2

The NM_000742.4(CHRNA2):c.1073G>T(p.Ser358Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000452 in 1,614,030 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000044 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 4.08

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.3054665).

BP6

Variant 8-27463370-C-A is Benign according to our data. Variant chr8-27463370-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 204968.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.

BS2

High AC in GnomAd4 at 9 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHRNA2	NM_000742.4 linkuse as main transcript	c.1073G>T	p.Ser358Ile	missense_variant	6/7	ENST00000407991.3	NP_000733.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHRNA2	ENST00000407991.3 linkuse as main transcript	c.1073G>T	p.Ser358Ile	missense_variant	6/7	5	NM_000742.4	ENSP00000385026	P2	Q15822-1

Frequencies

GnomAD3 genomes

AF:

0.0000592

AC:

AN:

152148

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:

0.000580

Gnomad SAS

AF:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000798

AC:

AN:

250536

Hom.:

AF XY:

0.000103

AC XY:

AN XY:

135468

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000544

Gnomad SAS exome

AF:

0.000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000438

AC:

AN:

1461764

Hom.:

Cov.:

AF XY:

0.0000605

AC XY:

AN XY:

727160

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000579

Gnomad4 SAS exome

AF:

0.000348

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000540

Gnomad4 OTH exome

AF:

0.0000828

GnomAD4 genome

AF:

0.0000591

AC:

AN:

152266

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74440

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000581

Gnomad4 SAS

AF:

0.000415

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000847

Hom.:

Bravo

AF:

0.0000718

ExAC

AF:

0.0000906

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jan 07, 2014

p.Ser358Ile (AGC>ATC): c.1073 G>T in exon 6 of the CHRNA2 gene (NM_000742.3). The S358I missense change has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. This variant is a non-conservative amino acid substitution, which is is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. However, this amino acid substitution occurs at a position that is not highly conserved across species and does not occur within the transmembrane region of the protein, where the vast majority of pathogenic missense mutations have been identified in association with epilepsy (Steinlein et al., 2010). In silico analysis is inconsistent with regard to the effect this variant may have on the protein structure/function. The variant is found in INFANT-EPI panel(s). -

Autosomal dominant nocturnal frontal lobe epilepsy 4

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 17, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.20

BayesDel_addAF

Benign

-0.19

BayesDel_noAF

Benign

-0.18

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.78

D;.;.

Eigen

Uncertain

0.40

Eigen_PC

Uncertain

0.38

FATHMM_MKL

Uncertain

0.88

LIST_S2

Benign

0.80

T;T;T

M_CAP

Uncertain

0.14

MetaRNN

Benign

0.31

T;T;T

MetaSVM

Uncertain

0.68

MutationAssessor

Pathogenic

3.3

M;.;.

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Benign

0.46

PROVEAN

Uncertain

-3.6

D;.;D

REVEL

Uncertain

0.55

Sift

Uncertain

0.0040

D;.;D

Sift4G

Uncertain

0.0090

D;D;D

Polyphen

0.45

B;.;.

Vest4

0.36

MutPred

0.44

Loss of disorder (P = 0.0048);.;.;

MVP

0.92

MPC

0.68

ClinPred

0.76

GERP RS

4.0

Varity_R

0.64

gMVP

0.56

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over