19-40843827-C-G

Variant names:

• chr19-40843827-C-G
• rs28399468
• NM_000762.6:c.1454G>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The ENST00000301141.10(CYP2A6):​c.1454G>C​(p.Arg485Pro) 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. 16/20 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: 30)
  • Exomes 𝑓: 0.0000014 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CYP2A6 ENST00000301141.10 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.24
• Publications: 27 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: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.047965795).

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000301141.10. 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.1454G>C	p.Arg485Pro	missense	Exon 9 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.1454G>C	p.Arg485Pro	missense	Exon 9 of 9	ENSP00000301141.4
	ENSG00000268797	ENST00000601627.1	TSL:3	n.117+42412C>G		intron	N/A	ENSP00000469533.1
	CYP2A6	ENST00000599960.1	TSL:2	n.373G>C		non_coding_transcript_exon	Exon 2 of 2

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD2 exomes AF: 0.00000800 AC: 2 AN: 249996 AF XY: 0.0000148

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000137 AC: 2 AN: 1460482 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 726554

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

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

American (AMR) AF: 0.0000224 AC: 1 AN: 44704

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 38734

South Asian (SAS) AF: 0.00 AC: 0 AN: 86168

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111820

Other (OTH) AF: 0.0000166 AC: 1 AN: 60306

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 30

ExAC AF: 0.0000165 AC: 2

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.43
CADD	Benign	0.86
DANN	Benign	0.90
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.018	N
LIST_S2	Benign	0.24	T
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.048	T
MetaSVM	Benign	-0.99	T
PhyloP100		-2.2
PrimateAI	Benign	0.38	T
PROVEAN	Benign	4.3	N
REVEL	Benign	0.13
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Vest4		0.079
MutPred		0.53		Gain of catalytic residue at P484 (P = 0.0107)
MVP		0.46
MPC		2.4
ClinPred		0.038	T
GERP RS		1.9
gMVP		0.70
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: rs28399468; hg19: chr19-41349732;