NM_000762.6:c.881C>T

Variant names:

• chr19-40846048-G-A
• rs4997557
• NM_000762.6:c.881C>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000762.6(CYP2A6):​c.881C>T​(p.Thr294Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,250 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CYP2A6 NM_000762.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.205
• Publications: 4 publications found

Genes affected

CYP2A6 (HGNC:2610): (cytochrome P450 family 2 subfamily A member 6) This gene, CYP2A6, encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and its expression is induced by phenobarbital. The enzyme is known to hydroxylate coumarin, and also metabolizes nicotine, aflatoxin B1, nitrosamines, and some pharmaceuticals. Individuals with certain allelic variants are said to have a poor metabolizer phenotype, meaning they do not efficiently metabolize coumarin or nicotine. This gene is part of a large cluster of cytochrome P450 genes from the CYP2A, CYP2B and CYP2F subfamilies on chromosome 19q. The gene was formerly referred to as CYP2A3; however, it has been renamed CYP2A6. [provided by RefSeq, Jul 2008]

CYP2A6 Gene-Disease associations (from GenCC):

• coumarin resistance

  Inheritance: Unknown Classification: NO_KNOWN Submitted by: Labcorp Genetics (formerly Invitae)
• nicotine dependence

  Inheritance: Unknown Classification: NO_KNOWN Submitted by: Labcorp Genetics (formerly Invitae)

ENSG00000268797 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.380653).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000762.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CYP2A6	NM_000762.6	MANE Select	c.881C>T	p.Thr294Ile	missense	Exon 6 of 9	NP_000753.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CYP2A6	ENST00000301141.10	TSL:1 MANE Select	c.881C>T	p.Thr294Ile	missense	Exon 6 of 9	ENSP00000301141.4
	CYP2A6	ENST00000596719.5	TSL:1	n.732C>T		non_coding_transcript_exon	Exon 5 of 6
	CYP2A6	ENST00000600495.1	TSL:1	n.*693C>T		non_coding_transcript_exon	Exon 6 of 6	ENSP00000472905.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460250 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 726442

African (AFR) AF: 0.00 AC: 0 AN: 33456

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 38440

South Asian (SAS) AF: 0.00 AC: 0 AN: 86150

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53364

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111934

Other (OTH) AF: 0.00 AC: 0 AN: 60286

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.50
BayesDel_addAF	Benign	-0.060	T
BayesDel_noAF	Benign	-0.32
CADD	Benign	18
DANN	Uncertain	0.98
Eigen	Benign	-0.70
Eigen_PC	Benign	-0.87
FATHMM_MKL	Benign	0.31	N
LIST_S2	Benign	0.71	T
M_CAP	Benign	0.035	D
MetaRNN	Benign	0.38	T
MetaSVM	Benign	-0.72	T
PhyloP100		-0.20
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-4.7	D
REVEL	Benign	0.29
Sift	Uncertain	0.0080	D
Sift4G	Uncertain	0.016	D
Vest4		0.44
MutPred		0.52		Loss of ubiquitination at K289 (P = 0.1423)
MVP		0.72
MPC		0.47
ClinPred		0.98	D
GERP RS		1.3
gMVP		0.33
Mutation Taster		=86/14	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: rs4997557; hg19: chr19-41351953;