- An alteration in DNA sequence caused by a single nucleotide base change, insertion, or deletion.
Definition from: GeneReviews
from the University of Washington and the National Center for Biotechnology Information
- A gene mutation involving the substitution, addition, or deletion of a single nucleotide base.
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
- A point mutation is when a single base pair is altered. Point mutations can have one of three effects. First, the base substitution can be a silent mutation where the altered codon corresponds to the same amino acid. Second, the base substitution can be a missense mutation where the altered codon corresponds to a different amino acid. Or third, the base substitution can be a nonsense mutation where the altered codon corresponds to a stop signal.
Definition from: Talking Glossary of Genetic Terms from the National Human Genome Research Institute
Related discussion in the Handbook
See also Understanding Medical Terminology.