A missense mutation is a change in the nucleic acid base sequence (e.g., the polynucleotide sequence found in DNA) that results in a change in the order of amino acids in the protein chain resulting from the translation of that sequence.

As with all mutations, a missense mutation is a change in a gene or chromosome. There are many types of mutations, including those resulting in a substitution of bases in the DNA sequence (i.e., one nucleotide is exchanged for another in the polynucleotide sequence. The effects of these mutations depend on the type, extent, and placement of the mutation in the DNA sequence. The effects of mutations range from silent mutations that do not result in a change in the translated protein sequence to mutations that are lethal and prevent embryonic development.

Changes in DNA sequencing are natural. Changes that occur during replication...