Transition Mutation

**Semantic type:** Cell or Molecular Dysfunction

**Definition:** A relatively common point mutation in which a purine is exchanged for a nonidentical purine or a pyrimidine is exchanged for a nonidentical pyrimidine. Base mispairing and mutagenic chemicals including nitrous acid and 5-bromo-2-deoxyuridine can result in transitions.

**Synonyms:** - Mutation, Transition - Nucleotide Transition Abnormality - Transition