rs140350483

Variant names:

• chr8-27463733-G-A
• rs140350483
• NM_000742.4:c.710C>T

Your query was ambiguous. Multiple possible variants found:

• chr8-27463733-G-A
• chr8-27463733-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000742.4(CHRNA2):​c.710C>T​(p.Thr237Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000031 in 1,613,938 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T237K) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: CHRNA2 NM_000742.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.51
• Publications: 2 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: 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

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNA2	NM_000742.4	c.710C>T	p.Thr237Met	missense_variant	Exon 6 of 7	ENST00000407991.3	NP_000733.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNA2	ENST00000407991.3	c.710C>T	p.Thr237Met	missense_variant	Exon 6 of 7	5	NM_000742.4	ENSP00000385026.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152048 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461890 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727246

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1112012

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152048 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74278

African (AFR) AF: 0.00 AC: 0 AN: 41386

American (AMR) AF: 0.00 AC: 0 AN: 15272

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

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5180

South Asian (SAS) AF: 0.00 AC: 0 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10606

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68000

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.0000140 Hom.: 0

Bravo AF: 0.0000264

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.088
BayesDel_addAF	Benign	-0.0086	T
BayesDel_noAF	Benign	-0.25
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.47	T;.;.
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Uncertain	0.89	D;D;D
M_CAP	Uncertain	0.17	D
MetaRNN	Uncertain	0.49	T;T;T
MetaSVM	Uncertain	-0.030	T
MutationAssessor	Benign	1.9	L;.;.
PhyloP100		6.5
PrimateAI	Benign	0.48	T
PROVEAN	Benign	-0.80	N;.;N
REVEL	Uncertain	0.44
Sift	Benign	0.037	D;.;D
Sift4G	Uncertain	0.016	D;D;D
Polyphen		0.97	D;.;.
Vest4		0.34
MutPred		0.48		Loss of sheet (P = 0.1907);.;.;
MVP		0.89
MPC		0.68
ClinPred		0.89	D
GERP RS		4.0
Varity_R		0.13
gMVP		0.57
Mutation Taster		=66/34	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: rs140350483; hg19: chr8-27321250;