Smoking Genes: A Case-Control Study of Dopamine Transporter Gene () and Dopamine Receptor Genes (, and ) Polymorphisms and Smoking Behaviour in a Malay Male Cohort.

Dopamine receptor and dopamine transporter genes polymorphisms have been associated with cigarette smoking behaviour in different populations. The aim of this case-control study was to evaluate polymorphisms in the dopamine transporter gene ( (rs27072)) and the dopamine receptor genes ( (rs686), (rs1800497) and (rs7653787)) and their contribution to smoking behaviour in a Malay male population. We identified 476 participants over the age of 18 years comprising 238 smokers and 238 non-smokers. Information such as age, height, weight, body mass index, systolic and diastolic blood pressures, marital status, and smoking status of close family members were taken. For the genetic study, we genotyped four genes ( (rs27072), (rs686), (rs1800497) and (rs7653787)) using the polymerase chain reaction-restriction fragment length polymorphism method and further confirmed our findings with sequencing. Dopamine receptor genes (, and ) were found to be associated with smoking behaviour in a Malay male population. The dopamine transporter gene () did not show this association. Significant differences were observed between smokers' and non-smokers' age, systolic blood pressure, marital status and family members who smoke. Smoking behaviour is significantly influenced by genetic variations of , and in a Malay male population.