title: Mitotic recombination can explain the apparent polyclonal origin of some tumors.
abstract: Although most human tumors appear to be monoclonal in origin, a few express two G6PD types; on this basis they have been thought to be polyclonal in origin and exceptions to the general rule of monoclonality. In light of the recent discovery that mitotic recombination can cause a shift from genetic heterozygosity to homozygosity in tumor cells, we suggest that such a mechanism can also explain the occasional occurrence of two G6PD types in a monoclonal tumor.
mesh_terms: D004303:Dosage Compensation, Genetic; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics; D006801:Humans; D008938:Mitosis; D009154:Mutation; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic
chemical_list: D005954:Glucosephosphate Dehydrogenase