DETECTION OF CHOLINERGIC RECEPTOR NICOTINIC ALPHA 3 SUBUNIT (CHRNA3 GENE-RS938682 G>A) GENE VARIATION IN NICOTINE DEPENDENT IN SMOKER AND NON-SMOKER POPULATION OF TABUK, SAUDI ARABIA.

Background: Nicotine acetylcholine receptor genes are expressed in the key regions of the brain and play an important role in controlling smoking behavior. Located on chromosome 15q25, they initiate the brain responses to nicotine that binds primarily to these receptors. Tobacco smoking is by far the greatest risk factor for developing lung cancer. Sequence variants in CHRNA SNPs on chromosome 15 have been associated with increased (self-reported) cigarette dose and nicotine dependence and increased risk of carcinogenesis including lung cancer in smokers. Therefore the aim of this study was to establish a rapid and sensitive molecular based assay like ARMS-PCR system for the detection of CHRNA3 gene-rs938682 G>A gene variations in smokers and nonsmokers. Methodology: This study was conducted on 100 specimens among whom 50 were smokers and 50 nonsmokers or healthy controls. DNA was extracted by Qiagen Kit and ARMS PCR system was optimized to detect CHRNA3 gene-rs938682 G>A gene variations in smokers and nonsmokers. Results: The study included 100 specimens among whom 50 were Smokers and 50 nonsmokers or healthy controls. The DNA quality and yield was assessed using Nanodrop (optical density) and 1% agarose gel electrophoresis .Genotyping for CHRNA3 -rs938682 G>A gene was performed on the genomic DNA using a tetra-primer ARMS PCR approach. The ARMS primers were designed by using Primer3 software. ARMS PCR was optimized using gradient PCR to detect CHRNA3-rs938682 G>A gene variations in Smokers and nonsmokers. In this study, it was successfully developed the ARMS technique using the wild-type or mutant-type primers with matched or one-base mismatched to examine the known SNPS in CHRNA3-rs938682 G>A gene. It was indicated that ARMS technique can be used as a potential molecular tool in the diagnosis of potential CHRNA3 gene variations for in smokers and nonsmokers. Conclusion: This study successfully developed the ARMS-PCR technique for the detection of SNPs in cholinergic receptor nicotinic alpha 3 subunit (CHRNA3 gene-rs938682 G>A) gene variation in smoker and nonsmoker population of Taluk. ARMS method could be useful for time-efficient, unbiased, sensitive, accurate, rapid, and reliable for CHRNA3 gene-rs938682 G>A other gene variations. Keywords: ARMS-PCR amplification-refractory mutation system ,CHRNA3 (cholinergic receptor nicotinic α3) SNP- Single-nucleotide polymorphism