8-27461689-G-A

Position:

chr8-27461689-G-A

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 0P and 8B. BP4_ModerateBP6BP7BS2

The NM_000742.4(CHRNA2):c.1530C>T(p.Ile510=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000639 in 1,614,232 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 0.00047 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00066 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 synonymous

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:5

Conservation

PhyloP100: -0.766

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 Benign. Variant got -8 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.38).

BP6

Variant 8-27461689-G-A is Benign according to our data. Variant chr8-27461689-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 362693.We mark this variant Likely_benign, oryginal submissions are: {Benign=3, Uncertain_significance=1, Likely_benign=2}. Variant chr8-27461689-G-A is described in Lovd as [Likely_benign].

BP7

Synonymous conserved (PhyloP=-0.766 with no splicing effect.

BS2

High AC in GnomAd4 at 71 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHRNA2	NM_000742.4 linkuse as main transcript	c.1530C>T	p.Ile510=	synonymous_variant	7/7	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.1530C>T	p.Ile510=	synonymous_variant	7/7	5	NM_000742.4	ENSP00000385026	P2	Q15822-1

Frequencies

GnomAD3 genomes

AF:

0.000466

AC:

AN:

152234

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000217

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.000852

Gnomad OTH

AF:

0.000956

GnomAD3 exomes

AF:

0.000414

AC:

104

AN:

251474

Hom.:

AF XY:

0.000419

AC XY:

AN XY:

135920

show subpopulations

Gnomad AFR exome

AF:

0.000431

Gnomad AMR exome

AF:

0.000260

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000738

Gnomad OTH exome

AF:

0.000651

GnomAD4 exome

AF:

0.000657

AC:

960

AN:

1461880

Hom.:

Cov.:

AF XY:

0.000616

AC XY:

448

AN XY:

727238

show subpopulations

Gnomad4 AFR exome

AF:

0.000209

Gnomad4 AMR exome

AF:

0.000246

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000814

Gnomad4 OTH exome

AF:

0.000563

GnomAD4 genome

AF:

0.000466

AC:

AN:

152352

Hom.:

Cov.:

AF XY:

0.000349

AC XY:

AN XY:

74502

show subpopulations

Gnomad4 AFR

AF:

0.000216

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000852

Gnomad4 OTH

AF:

0.000946

Alfa

AF:

0.000687

Hom.:

Bravo

AF:

0.000484

EpiCase

AF:

0.000654

EpiControl

AF:

0.000771

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	May 18, 2018	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Nov 12, 2018	- -

not specified

Benign:1

Benign, criteria provided, single submitter

clinical testing

Athena Diagnostics

Apr 11, 2017

- -

Autosomal dominant nocturnal frontal lobe epilepsy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 17, 2024

- -

Inborn genetic diseases

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 08, 2017

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Autosomal dominant nocturnal frontal lobe epilepsy 4

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.38

CADD

Benign

6.7

DANN

Benign

0.85

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