[Genetic basis of individual susceptibility]

Polymorphic forms of genes involved in the control of the various phases of the cancerogenic process were associated to a greater individual susceptibility to cancer as a consequence of exposures to environmental carcinogenic agents. Some of these genes are involved in xenobiotic metabolism, in replication and repair of the DNA, in the control of cell cycle and cellular proliferation, of apoptosis, of the inflammation process, etc. Although the specific risk associated to a single polymorphic gene is generally low, the sanitary meaning can be considerable if the frequency of certain polymorphisms is high and the exposure is consistent. Furthermore, the combination of more unfavourable alleles can determine high risk genotypes. These subjects, probably, will fall ill as consequence of an exposure. The development of methodologies which allow the genotyping of a big number of genes can allow the identifying of highly susceptible subjects.