Association of Nicotine Use Disorder with Neurexin 3 Gene Polymorphisms.

Objective: In this study, we aimed to investigate the Neurexin 3 gene (NRXN3) polymorphisms in the rs 221473, rs 221497, rs1004212 and rs11624704 regions in relation to nicotine use disorder (NUD) in the Turkish population.

Method: Power analysis indicated that the NUD group and the control group of this study should each comprise 200 participants in the 18-65 year age range. The NUD group consisted of individuals without a psychiatric first axis disorder except for NUD, mental retardation, past head trauma or a neurological disorder, who had smoked minimally10 cigarettes per day for at least 1 year. The control group included individuals without a serious chronic physical illness, a previous psychiatric disorder or mental retardation and who responded "no" to the question "have you ever smoked?" A sociodemographic questionnaire and the Fageström nicotine dependence scale (FNDS) for the NUD group were utilized. Venous blood samples of all participants were taken into tubes containing EDTA (ethylene daimine tetra acetic acid) for DNA extraction. Duplex fluorescence melting curve analysis was used for genotype detection and differentiation.

Results: The individuals carrying the AC allele and the AG allele at the rs11624704 and the rs1004212 regions respectively had a high risk of being addicted to cigarettes.

Conclusion: This is first study investigating the relationship of the NRXN3 gene and nicotine addiction in the Turkish population. It was observed that the risk of NUD in the Turkish population may be related to the Neurexin gene.