Data on polymorphisms in CYP2A6 associated to risk and predispose to smoking related variables

This article contains data on the single nucleotide polymorphisms (SNPs) rs1137115, rs1801272 and rs28399433 rs4105144 in CYP2A6 associated to smoking related variables in Mexican Mestizo smokers (Pérez-Rubio et al., 2017) [1]. These SNPs were selected due to previous associations with other populations. Mexican Mestizo smokers were classified according their smoking pattern. A genetic association test was performed.


Specifications
Mexican mestizo smokers who carry some risk alleles in CYP2A6 could predispose to smoking behavior variables.

Subjects
We selected subjects with Z40 years old, men and women. To determine Mexican Mestizo ancestry, subjects were asked about their parents and grandparents ancestry and not belong to an indigenous group.
Smokers recruited from the Smoking Cessation Support Clinic of the Department of Investigation in Tobacco Consumption and COPD at the Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas (INER) in Mexico City, with the following criteria: had 10 Zyears smoking were classified according their smoking pattern in cigarette smoking per day (cpd) into light smokers (LS r 10 cpd) and heavy smokers (HSZ 20 cpd), these subjects has been recruited previously in our research group [2,3]. A reference group of never-smokers healthy volunteers was selected with the same demographic characteristics.

Smoking pattern variables
A survey with smoking related variables were assed to daily smokers. They were asked about their age at onset smoking, cigarette smoking per day (cpd) and years of smoking.

DNA extraction
A 15 mL peripheral blood sample in tubes with EDTA was obtained from each participant through venipuncture. DNA extraction was performed using BDtract DNA isolation kit (Maxim Biotech, Inc. San Francisco, California, USA) and later was quantified with a NanoDrop 2000 (Thermo Scientific, DE, USA). DNA samples with a concentration 4100 ng/mL and purity with a 260/280 relation Z2.

SNP selection
We searched publications from 2010 to 2015 on genetic association studies performed in Caucasian, Asian and African populations. We identified rs1137115, rs1801272 and rs28399433 in CYP2A6 and rs4105144 near the gene.

Genotyping
Genotyping was performed using a real-time PCR (7300 Real-Time PCR system, Applied Biosystems, Foster City, CA, USA) based allelic discrimination assay using 3 μL of DNA at 15 ng/μL concentration and TaqMan probes (Applied Biosystems Foster City CA, USA). In each template, we included 3 non-template controls, and 1% of the samples were genotyped in duplicate as an allele assignment control. Sequence Detection Software (SDS v. 1.4, Applied Biosystems). VIC™ and FAM™ dyes were used for alleles A and B, respectively (Fig. 2).

Statistical analyses
To describe the study population, we used the statistical software SPSS v.20.0 (IBM, New York, USA) in which we calculated the mean and standard deviation of each continuous quantitative variable and the percentage for the genre. All SNPs genotyped were evaluated in the control group (NS) using the Hardy-Weinberg test. Haplotype analysis was performed using Haploview version 4.2.

Genetic association
Genetic association was tested in different models: full genotype, dominant, recessive and by allele using Epidat version 3. To identify SNPs associated with increased nicotine addiction, we compared HS vs. LS, and to associate SNPs with cigarette consumption, we compared HS vs. NS and LS vs. NS (Table 1, Fig. 3).

Ethical approval
The protocol was approved by INER science and research bioethics and biosecurity committees (protocol number B15-16).

Transparency document. Supporting information
Transparency data associated with this article can be found in the online version at http://dx.doi. org/10.1016/j.dib.2017.09.013.