Insertion (genetics)

Insertion (genetics)

In genetics, an insertion (also called an insertion mutation) is the addition of one or more nucleotide base pairs into a DNA sequence. This can often happen in microsatellite regions due to the DNA polymerase slipping. Insertions can be anywhere in size from one base pair incorrectly inserted into a DNA sequence to a section of one chromosome inserted into another.

On a chromosome level, an insertion refers to the insertion of a larger sequence into a chromosome. This can happen due to unequal crossover during meiosis.

N region addition is the addition of non-coded nucleotides during recombination by terminal deoxynucleotidyl transferase.

P nucleotide insertion is the insertion of palindromic sequences encoded by the ends of the recombining gene segments.

Trinucleotide repeats are sometimes classified as insertion mutations and sometimes as a separate class of mutations.