19-40846953-C-A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000762.6(CYP2A6):​c.753G>T​(p.Lys251Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000496 in 1,612,120 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. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000040 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

CYP2A6
NM_000762.6 missense

Scores

1
3
13

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.418

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: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.26102498).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CYP2A6NM_000762.6 linkc.753G>T p.Lys251Asn 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.753G>T p.Lys251Asn missense_variant Exon 5 of 9 1 NM_000762.6 ENSP00000301141.4 P11509
ENSG00000268797ENST00000601627.1 linkn.118-45038C>A intron_variant Intron 1 of 3 3 ENSP00000469533.1 M0QY20

Frequencies

GnomAD3 genomes
AF:
0.0000395
AC:
6
AN:
151748
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000864
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.000957
GnomAD2 exomes
AF:
0.0000478
AC:
12
AN:
251136
AF XY:
0.0000368
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.000496
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000528
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000507
AC:
74
AN:
1460256
Hom.:
0
Cov.:
31
AF XY:
0.0000578
AC XY:
42
AN XY:
726434
show subpopulations
African (AFR)
AF:
0.0000897
AC:
3
AN:
33456
American (AMR)
AF:
0.00
AC:
0
AN:
44714
Ashkenazi Jewish (ASJ)
AF:
0.000421
AC:
11
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38438
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86150
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53370
Middle Eastern (MID)
AF:
0.00382
AC:
22
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000279
AC:
31
AN:
1111950
Other (OTH)
AF:
0.0000995
AC:
6
AN:
60280
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.466
Heterozygous variant carriers
0
4
9
13
18
22
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:
0.0000395
AC:
6
AN:
151864
Hom.:
0
Cov.:
32
AF XY:
0.0000674
AC XY:
5
AN XY:
74222
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41424
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.000864
AC:
3
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
4996
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4784
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10586
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68008
Other (OTH)
AF:
0.000949
AC:
2
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.000113
Hom.:
0
Bravo
AF:
0.0000378
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000495
AC:
6
EpiCase
AF:
0.000109
EpiControl
AF:
0.0000593

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Jul 05, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.753G>T (p.K251N) alteration is located in exon 5 (coding exon 5) of the CYP2A6 gene. This alteration results from a G to T substitution at nucleotide position 753, causing the lysine (K) at amino acid position 251 to be replaced by an asparagine (N). 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
Pathogenic
0.77
BayesDel_addAF
Benign
-0.25
T
BayesDel_noAF
Benign
-0.42
CADD
Benign
16
DANN
Uncertain
1.0
Eigen
Benign
-0.099
Eigen_PC
Benign
-0.29
FATHMM_MKL
Benign
0.18
N
LIST_S2
Benign
0.23
T
M_CAP
Benign
0.023
T
MetaRNN
Benign
0.26
T
MetaSVM
Benign
-0.70
T
PhyloP100
-0.42
PrimateAI
Uncertain
0.60
T
PROVEAN
Uncertain
-2.4
N
REVEL
Benign
0.29
Sift
Benign
0.065
T
Sift4G
Benign
0.094
T
Vest4
0.44
MutPred
0.60
Loss of ubiquitination at K251 (P = 0.0283);
MVP
0.69
MPC
0.50
ClinPred
0.55
D
GERP RS
-0.032
gMVP
0.54
Mutation Taster
=76/24
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: rs374784083; hg19: chr19-41352858; COSMIC: COSV56535086; COSMIC: COSV56535086; API