The relationship between DRD2 TaqIA polymorphism and tobacco addiction
Esma Ulusoy1, Mehtap Çevik2, Belgin Süsleyici2
1Department of Molecular Biology and Genetics, Yıldız Technical University, Istanbul, Turkey
2Department of Molecular Biology, Marmara University, Istanbul, Turkey
Keywords: Dopamine, DRD2 gene, polymorphism, TaqIA, tobacco addiction.
Objectives: In this study, the relationship between tobacco addiction levels, early smoking, and DRD2 TaqIA polymorphism was investigated.
Materials and methods: The present study included 36 smokers and 12 non-smoking voluntary controls. Study groups were established as the non-smoking control group and addicted (less than 1 pack, between 1-2 packs, more than 2 packs per day) groups. Genotypes of the dopamine type-2 receptor (DRD2) gene TaqIA polymorphic region from genomic DNA isolated from oral swab samples were determined by PCR followed by Restriction Fragment Length Polymorphism (RFLP) analysis.
Results: Presence of the DRD2 TaqIA homozygous polymorphic genotype in addicted individuals who smoked two or more packs per day and the absence of non-smoker control individuals may indicate that the polymorphic TaqIA allele of the DRD2 gene is associated with smoking. It was found that individuals carrying the polymorphic TaqIA allele in homozygous (~13 years) and heterozygous forms (~16.3 years) had a lower age of starting smoking compared to homozygous wild types (~18.6 years). Mean BMI (body mass index) of the study participants was 24.66 kg/m2 (normal weight), waist/hip ratio 0.82 (no abdominal obesity).
Conclusion: The results of our study suggest that the TaqIA variant allele is related to early smoking condition. In addition, it was determined that there was a higher tendency of smoking addiction among children of addicted parents.