Different types of indel<unk> . Panel C is simply a deletion and not a<unk> . A<unk>  (also called a framing error or a reading<unk>  is a genetic<unk>  caused by indels (insertions or deletions) of a number of nucleotides in a DNA sequence that is not divisible by three. Due to the triplet nature of gene expression by codons, the insertion or deletion can change the reading frame (the grouping of the codons), resulting in a completely different translation from the original. The earlier in the sequence the deletion or insertion occurs, the more altered the protein. A<unk>  is not the same as a single-nucleotide polymorphism in which a nucleotide is replaced, rather than inserted or deleted. A<unk>  will in general cause the reading of the codons after the<unk>  to code for different amino acids. The<unk>  will also alter the first stop codon ("UAA", "UGA" or "UAG") encountered in the sequence. The polypeptide being created could be abnormally short or abnormally long, and will most likely not be functional.<unk> s are apparent in severe genetic diseases such as Tay–Sachs disease; they increase susceptibility to certain cancers and classes of familial hypercholesterolaemia; in 1997, a<unk>  was linked to resistance to infection by the HIV retrovirus.<unk> s have been proposed as a source of biological novelty, as with the alleged creation of nylonase, however, this interpretation is controversial. A study by Negoro et al (2006) found that a<unk>  was unlikely to have been the cause and that rather a two amino acid substitution in the active site of an ancestral esterase resulted in nylonase.
Frameshift mutation
Exon skipping
Exon shuffling
Deletion 
Fusion transcript
Efference copy
Osseoincorporation
Copy number variation