Genetic Variant NM_000742.4:c.1176C>T (chr8-27463267-G-A) – ACMG Classification: Benign (-17 pts)

Variant summary

Our verdict is Benign. The variant received -17 ACMG points: 0P and 17B. BP4_StrongBP6_Very_StrongBP7BS2

The NM_000742.4(CHRNA2):c.1176C>T(p.Pro392Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000367 in 1,605,876 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 Likely benign (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

CHRNA2
NM_000742.4 synonymous

Scores

Clinical Significance

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

Conservation

PhyloP100: -0.686

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: Benign. The variant received -17 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.88).

BP6

Variant 8-27463267-G-A is Benign according to our data. Variant chr8-27463267-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 512597.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=-0.686 with no splicing effect.

BS2

High AC in GnomAdExome4 at 55 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.1176C>T	p.Pro392Pro	synonymous	Exon 6 of 7	NP_000733.2	Q15822-1
CHRNA2	NM_001282455.2		c.1131C>T	p.Pro377Pro	synonymous	Exon 6 of 7	NP_001269384.1	Q15822-2
CHRNA2	NM_001347705.2		c.699C>T	p.Pro233Pro	synonymous	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.1176C>T	p.Pro392Pro	synonymous	Exon 6 of 7	ENSP00000385026.1	Q15822-1
CHRNA2	ENST00000523695.5	TSL:1	n.*578C>T		non_coding_transcript_exon	Exon 6 of 7	ENSP00000430612.1	E5RJ54
CHRNA2	ENST00000523695.5	TSL:1	n.*578C>T		3_prime_UTR	Exon 6 of 7	ENSP00000430612.1	E5RJ54

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152212

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:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000897

AC:

AN:

245392

AF XY:

0.000136

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000582

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000182

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000378

AC:

AN:

1453546

Hom.:

Cov.:

AF XY:

0.0000624

AC XY:

AN XY:

721554

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33364

American (AMR)

AF:

0.0000225

AC:

AN:

44520

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25748

East Asian (EAS)

AF:

0.00

AC:

AN:

39556

South Asian (SAS)

AF:

0.000573

AC:

AN:

85524

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52900

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5730

European-Non Finnish (NFE)

AF:

0.00000181

AC:

AN:

1106218

Other (OTH)

AF:

0.0000500

AC:

AN:

59986

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.506

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:

0.0000263

AC:

AN:

152330

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74468

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41570

American (AMR)

AF:

0.00

AC:

AN:

15304

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.000621

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.508

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:

0.0000712

Hom.:

Bravo

AF:

0.0000151

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)

not provided (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.88

CADD

Benign

0.41

(source)

DANN

Benign

0.50

PhyloP100

-0.69

Mutation Taster

=100/0

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

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over