chr19-40846886-G-A

Variant summary

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

The NM_000762.6(CYP2A6):​c.820C>T​(p.Arg274Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,611,878 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

CYP2A6
NM_000762.6 missense

Scores

2
4
11

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.0270

Publications

1 publications found
Variant links:
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)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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
CYP2A6NM_000762.6 linkc.820C>T p.Arg274Cys missense_variant Exon 5 of 9 ENST00000301141.10 NP_000753.3 P11509

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CYP2A6ENST00000301141.10 linkc.820C>T p.Arg274Cys missense_variant Exon 5 of 9 1 NM_000762.6 ENSP00000301141.4 P11509
ENSG00000268797ENST00000601627.1 linkn.118-45105G>A intron_variant Intron 1 of 3 3 ENSP00000469533.1 M0QY20

Frequencies

GnomAD3 genomes
AF:
0.0000264
AC:
4
AN:
151726
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000288
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000797
AC:
2
AN:
250928
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000185
AC:
27
AN:
1460152
Hom.:
0
Cov.:
31
AF XY:
0.0000234
AC XY:
17
AN XY:
726380
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33458
American (AMR)
AF:
0.00
AC:
0
AN:
44710
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38428
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86118
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53366
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000234
AC:
26
AN:
1111898
Other (OTH)
AF:
0.00
AC:
0
AN:
60280
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.445
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000264
AC:
4
AN:
151726
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74072
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41282
American (AMR)
AF:
0.00
AC:
0
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.000288
AC:
1
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5010
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4794
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10582
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68010
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000434
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Aug 13, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.820C>T (p.R274C) alteration is located in exon 5 (coding exon 5) of the CYP2A6 gene. This alteration results from a C to T substitution at nucleotide position 820, causing the arginine (R) at amino acid position 274 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.22
BayesDel_addAF
Benign
-0.070
T
BayesDel_noAF
Benign
-0.32
CADD
Uncertain
25
DANN
Uncertain
1.0
Eigen
Benign
-0.31
Eigen_PC
Benign
-0.37
FATHMM_MKL
Benign
0.18
N
LIST_S2
Benign
0.75
T
M_CAP
Uncertain
0.12
D
MetaRNN
Uncertain
0.55
D
MetaSVM
Benign
-0.45
T
PhyloP100
0.027
PrimateAI
Benign
0.39
T
PROVEAN
Pathogenic
-5.3
D
REVEL
Benign
0.20
Sift
Uncertain
0.0090
D
Sift4G
Pathogenic
0.0
D
Vest4
0.45
MutPred
0.55
Loss of disorder (P = 0.0371);
MVP
0.79
MPC
0.53
ClinPred
0.96
D
GERP RS
1.1
gMVP
0.42
Mutation Taster
=94/6
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

Publications

Other links and lift over

dbSNP: rs780129128; hg19: chr19-41352791; COSMIC: COSV99991832; COSMIC: COSV99991832; API