A silent mutation is any change in DNA or RNA (mutation) that does not result in a change in the function of the protein. With silent mutations, the function of the protein coded for by the gene undergoing the mutational event remains unaltered.

In structural genes, a silent mutation can result from a change in the base sequence of DNA (or, in prokaryotes, RNA) that does not result in a change in the amino acid sequence of the protein for which the gene carries instructions. The genetic code is termed a degenerate code because more than one base sequence (and the codons produced from them) may code for a particular amino acid. Accordingly, a change from one sequence to another does not result in a change in the amino acid sequence of the protein. There are, for example, six different nucleotide sequences and codons that direct...