3.2. Genetic susceptibility
Genetically determined variations in biotransformation enzymes, target molecules or cellular repair processes can modify the response to exogenous agents including OPs. This area of research on gene-environment interactions, known as ecogenetics, is aimed at identifying genetic polymorphisms that may modify the risk for adverse health effects upon exposure to a xenobiotic [40], [41] and [42]. In case of OPs, genetic polymorphisms in biotransformation enzymes or target molecules can affect their toxicity [43] and [44]. As discussed earlier, CYPs are important for the activation and detoxication of OP insecticides. Variant forms of several CYP genes have been identified, and these polymorphisms confer differences in catalytic activity or level of expression, which may result in varying rates of oxidation of xenobiotics among individuals [45]. However, as information on the role of specific CYP isozymes in the metabolism of OPs is just beginning to emerge, very limited information is available on the potential contribution of such genetic polymorphisms to OP toxicity susceptibility.