dbSNP rs3735757: CHRNA2:c.450-87C>T (chr8-27464080-G-A) – ACMG Classification: Benign (-8 pts)

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_StrongBS2

The NM_000742.4(CHRNA2):c.450-87C>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000054 in 1,518,470 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000054 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 intron

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -2.02

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:

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ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -8 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.9).

BS2

High AC in GnomAd4 at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNA2	NM_000742.4 link	c.450-87C>T		intron_variant	Intron 5 of 6	ENST00000407991.3	NP_000733.2	Q15822-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNA2	ENST00000407991.3 link	c.450-87C>T		intron_variant	Intron 5 of 6	5	NM_000742.4	ENSP00000385026.1		Q15822-1

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152040

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:

0.000377

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.0000542

AC:

AN:

1366430

Hom.:

AF XY:

0.0000514

AC XY:

AN XY:

680394

show subpopulations

Gnomad4 AFR exome

AF:

0.0000321

AC:

AN:

31184

Gnomad4 AMR exome

AF:

0.00

AC:

AN:

38772

Gnomad4 ASJ exome

AF:

0.00

AC:

AN:

25162

Gnomad4 EAS exome

AF:

0.00

AC:

AN:

37140

Gnomad4 SAS exome

AF:

0.00

AC:

AN:

81346

Gnomad4 FIN exome

AF:

0.000753

AC:

AN:

50484

Gnomad4 NFE exome

AF:

0.0000307

AC:

AN:

1041304

Gnomad4 Remaining exome

AF:

0.0000527

AC:

AN:

56938

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

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:

0.0000526

AC:

AN:

152040

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74254

show subpopulations

Gnomad4 AFR

AF:

0.00

AC:

AN:

Gnomad4 AMR

AF:

0.00

AC:

AN:

Gnomad4 ASJ

AF:

0.00

AC:

AN:

Gnomad4 EAS

AF:

0.00

AC:

AN:

Gnomad4 SAS

AF:

0.00

AC:

AN:

Gnomad4 FIN

AF:

0.000377

AC:

0.000377145

AN:

0.000377145

Gnomad4 NFE

AF:

0.0000588

AC:

0.0000588166

AN:

0.0000588166

Gnomad4 OTH

AF:

0.00

AC:

AN:

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

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:

0.00

Hom.:

2556

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.90

CADD

Benign

1.7

DANN

Benign

0.91

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

Computational scores

Splicing

Publications

LitVar

Other links and lift over