American Association for Cancer Research


mutation: A heritable change in the sequence of the DNA. Mutations can result from errors in DNA replication or from DNA damage and can range from changes in a single base pair (point mutation) to gross changes in a chromosome (duplication, translocation, inversion, deletion). Not all mutations are harmful—some occur in regions of DNA that do not encode a gene, and some occur in a gene but do not change the function of the gene or the eventual amino acid sequence of the protein. Mutations in the DNA of somatic cells will be passed on to the daughter cells during cell division. Mutations in the DNA of a gamete will be inherited by subsequent generations of offspring. Also called a genetic change.

For more glossary words, visit the Glossary of Cancer Terms.