Gene polymorphism and risk of oral cancer in a south indian population a case control study

Abstract

This thesis describes the associat ion of twelve important single nucleot ide polymorphisms from four detoxificat ion genes (CYP1A1, CYP2E, EPHX1 and NAT2) with oral cancer in the South Indian populat ion. The subjects included 157 histopathologically confirmed of oral cancer patients and 132 control individuals who newlinereported the absences of personal history of cancer . The genotyping newlinewas done by TaqMan al lel ic discriminat ion. The associat ions between genotypes, alleles and haplotypes of the polymorphic sites newlineand oral cancer were then analyzed using a case -control study. The strength of the association between gene variants and oral cancer was estimated using the logistic regression. The genotype frequencies of al l polymorphic SNPs were consistent wi th Hardy - Weinbergequilibrium in the cont rolgroup. The CYP1A1-Thr461Asn and CYP2E1-V179I loci are not polymorphic in the present study, whereas rs3813867 and rs2031920 newlineare co-inheri ted. Al l the polymorphisms studied in EPHX1 and NAT2 genes were polymorphic in both cases and cont rols. For al l newlinethe genes, there were no significant differences in genotype or newlinehaplotype f requencies between cont rols and cases wi th oral cancer. newlineOf the EPHX1, NAT2 gene polymorphisms studied, two were in strong l inkage disequi l ibrium and form 1 haplotype block in the respect ive genes. The overal l acetylator phenotypes, showed stat ist ical ly newlinesigni ficant associat ion, in par t icular , rapid acetylator genotypes, to newlineoral cancer r isk. Lack of a signi ficant associat ion between newlinedetoxificat ion gene polymorphisms and oral cancer in the present newlinestudy might be explained by the substant ial ly lower f requencies of newlinethese al leles. Further , the resul ts are discussed in the l ight of newlinedetoxificat ion of carcinogens found in tobacco smoke and alcohol.