DEFINITION: FRAMESHIFT
A type of mutation that causes the cellular machinery to parse the DNA code differently and produce a different protein. Each sequence of three base pairs codes for an amino acid. If, for example, you add a single base pair in the middle of the sequence, it changes where each subsequent set of three base pairs begins and ends—and hence, changes the amino acid sequence produced. Frameshifts are caused by insertions and deletions where the number of base pairs added or removed is not a multiple of three.