Indel is a portmanteau of insertion and deletion, referring to the two types of genetic mutation that are often considered together because of their similar effect. Unless the length of an indel is a multiple of 3, they produce a frameshift mutation. They present a particular problem in protein homology modelling.

Indels can be contrasted with a substitution; Where an Indel replaces or deletes single nucleotides or whole sections of DNA from a sequence, a substitution only replaces one of the molecules (called a nucleotide) that join the DNA. The replacement is made by substituting in one of the remaining three possible molecules.

"Indel" mutation of a single DNA base causes "frameshift" when translating mRNA, and this can result in "missense" codon and perhaps inappriate stop codons.

portmanteaus | mutation