Germline gene polymorphisms predisposing domestic mammals to carcinogenesis.

Cancer is a complex disease caused in part by predisposing germline gene polymorphisms. Knowledge of carcinogenesis in companion mammals (dog and cat) and some livestock species (pig and horse) is quite advanced. The prevalence of certain cancers varies by breed in these species, suggesting the presence of predisposing genetic variants in susceptible breeds. This review summarizes the present understanding of germline gene polymorphisms, including BRCA1, BRCA2, MC1R, KIT, NRAS and RAD51, associated with predisposition to melanoma, mammary cancer, osteosarcoma and histiocytic sarcoma in dogs, cats, pigs and horses. The predisposing variants in these species are discussed in the context of human germline gene polymorphisms associated with the same types of cancer.