title: A novel form of human polymorphism involving the hDHFR-psi 1 pseudogene identifies three RFLPs.
mesh_terms: D005787:Gene Frequency; D005796:Genes; D006801:Humans; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*
chemical_list: D013762:Tetrahydrofolate Dehydrogenase