Nonassociation of aryl hydrocarbon receptor genotypes with susceptibility to bladder cancer in Shanghai population.
AIM
To assess two polymorphic forms of aryl hydrocarbon receptor (AHR) gene, G1721A (R554K), and G1768A (V570I) in Chinese population and to explore the possible association of human AHR gene polymorphism with elevated incidence of bladder cancer among Chinese Han subjects in east of China.


METHODS
An allele specific PCR-based procedure for AHR gene polymorphism genotyping was developed by this work. Genotyping on three groups of subjects in Shanghai area had been performed: a bladder cancer group with the occupational exposure to benzidine, a non-occupational bladder cancer patient group whose members lack an obvious aromatic amine exposure record, and a normal population in the same city as controls.


RESULTS
A significant difference (P < 0.01) in frequency distribution at locus G1721A between normal population in Shanghai and a Caucasian population reported by other authors was observed. No mutant allele(A1768) at locus G1768A had ever been detected in our study. The observed frequencies were similar between both genders in the normal population (P = 0.54), and there were no significant difference confirmed between the case group and the control group.


CONCLUSION
The locus G1768 of human AHR gene seems to be monomorphic among Chinese in this area. The significant distribution difference at locus G1721A of human AHR gene between Chinese Han and Caucasian was confirmed. This study did not support the association of AHR G1721A polymorphism with higher risk to bladder cancer among the residents in this area, either in a group of occupationally benzidine-exposed individuals or among the persons who never have an obvious aromatic amine exposure record.