19-40850405-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000762.6(CYP2A6):c.22C>G(p.Leu8Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/19 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. L8L) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CYP2A6 NM_000762.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.53

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.11007497).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CYP2A6	NM_000762.6	c.22C>G	p.Leu8Val	missense_variant	1/9	ENST00000301141.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CYP2A6	ENST00000301141.10	c.22C>G	p.Leu8Val	missense_variant	1/9	1	NM_000762.6	P1
CYP2A6	ENST00000596719.5	n.36C>G		non_coding_transcript_exon_variant	1/6	1
CYP2A6	ENST00000600495.1	c.22C>G	p.Leu8Val	missense_variant, NMD_transcript_variant	1/6	1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.087
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.48
Cadd	Benign	13
Dann	Benign	0.65
Eigen	Benign	-0.93
Eigen_PC	Benign	-0.94
FATHMM_MKL	Benign	0.19	N
LIST_S2	Benign	0.59	T
M_CAP	Benign	0.012	T
MetaRNN	Benign	0.11	T
MetaSVM	Benign	-0.81	T
MutationTaster	Benign	1.0	P
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-0.50	N
REVEL	Benign	0.12
Sift	Benign	0.43	T
Sift4G	Benign	0.28	T
Vest4		0.30
MutPred		0.38		Gain of catalytic residue at L8 (P = 0.0065);
MVP		0.44
MPC		0.11
ClinPred		0.27	T
GERP RS		3.0
gMVP		0.33

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

Other links and lift over

dbSNP: rs8192720; hg19: chr19-41356310;