noun, plural: frameshift mutations
(genetics) A type of gene mutation wherein the addition or deletion of (a number of) nucleotide(s) causes a shift in the reading frame of the codons in the mRNA, thus, may eventually lead to the alteration in the amino acid sequence at protein translation
Mutation is a change in the nucleotide sequence of a gene or a chromosome. Based on the effect of mutation on the gene structure, mutations may be: (1) small-scale mutations or (2) large scale mutations. Small-scale mutations are a type of mutation where one or few nucleotides of a gene are affected. They are further classified as follows: (1) substitution mutations, (2) insertion mutations, and (3) deletion mutations. Frameshift mutation occurs due to indels (i.e. insertions or deletions) of a number of nucleotides in a DNA sequence that is not divisible by three.
Frameshift mutations may be beneficial, deleterious, or lethal. For example, induction of frameshift mutation has been used to make certain bacteria capable of producing nylonase, an enzyme that can degrade nylon.
Frameshift mutation has also been one of the possible causes of albinism. A shift in the reading frame can lead to formation of stop codon, hence, early terminating protein translation. An early termination of any of the enzymes necessary for the production of melanin can result in albinism. Tay Sachs disease is an example of a disease caused by frameshift mutation. The disease is caused by various mutations, including frameshift mutations, on chromosome 15 in the HEXA gene that codes for the alpha–subunit of the lysosomal enzyme beta-N-acetylhexosaminidase A.
- frame shift mutation