Medical Definition of Mutation, null
Mutation, null: A mutation (a change) in a gene that leads to its not being transcribed into RNA and/or translated into a functional protein product.
For example, a null mutation in a gene that usually encodes a specific enzyme leads to the production of a nonfunctional enzyme or no enzyme at all.Source: MedTerms™ Medical Dictionary
Last Editorial Review: 9/14/2016
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