chr8-27460183-T-C

Variant names:

• chr8-27460183-T-C
• rs28697263
• NM_000742.4:c.*1446A>G

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_Strong BP6_Moderate BS2

The NM_000742.4(CHRNA2):​c.*1446A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0038 in 152,210 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

• Frequency:
  • Genomes: 𝑓 0.0038 (2 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CHRNA2 NM_000742.4 3_prime_UTR
• Clinical Significance: Benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.123
• Publications: 0 publications found

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: Labcorp Genetics (formerly Invitae), Illumina, G2P
• 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

ACMG classification

Our verdict: Benign. The variant received -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.93).
• BP6: Variant 8-27460183-T-C is Benign according to our data. Variant chr8-27460183-T-C is described in ClinVar as Benign. ClinVar VariationId is 362667.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS2: High AC in GnomAd4 at 578 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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRNA2	NM_000742.4	MANE Select	c.*1446A>G		3_prime_UTR	Exon 7 of 7	NP_000733.2	Q15822-1
	CHRNA2	NM_001282455.2		c.*1446A>G		3_prime_UTR	Exon 7 of 7	NP_001269384.1	Q15822-2
	CHRNA2	NM_001347705.2		c.*1446A>G		3_prime_UTR	Exon 7 of 7	NP_001334634.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRNA2	ENST00000407991.3	TSL:5 MANE Select	c.*1446A>G		3_prime_UTR	Exon 7 of 7	ENSP00000385026.1	Q15822-1

Frequencies

GnomAD3 genomes AF: 0.00379 AC: 576 AN: 152092 Hom.: 2 Cov.: 32

Gnomad AFR AF: 0.0132

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00157

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: 0.0000147

Gnomad OTH AF: 0.00144

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 56 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 44

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AF: 0.00 AC: 0 AN: 4

South Asian (SAS) AC: 0 AN: 0

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 2

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 50

Other (OTH) AC: 0 AN: 0

GnomAD4 genome AF: 0.00380 AC: 578 AN: 152210 Hom.: 2 Cov.: 32 AF XY: 0.00382 AC XY: 284 AN XY: 74424

African (AFR) AF: 0.0132 AC: 550 AN: 41532

American (AMR) AF: 0.00157 AC: 24 AN: 15296

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5162

South Asian (SAS) AF: 0.00 AC: 0 AN: 4814

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68000

Other (OTH) AF: 0.00142 AC: 3 AN: 2112

Alfa AF: 0.00192 Hom.: 0

Bravo AF: 0.00451

Asia WGS AF: 0.000866 AC: 3 AN: 3478

ClinVar

ClinVar submissions as Germline

Significance: Benign

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	-	1	Autosomal dominant nocturnal frontal lobe epilepsy 4 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.93
CADD	Benign	2.1
DANN	Benign	0.41
PhyloP100		-0.12
Mutation Taster		=100/0	polymorphism

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

Other links and lift over

dbSNP: rs28697263; hg19: chr8-27317700;