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updated: September 23, 2023


An insertion, as related to genomics, is a type of mutation that involves the addition of one or more nucleotides into a segment of DNA. An insertion can involve the addition of any number of nucleotides, from a single nucleotide to an entire piece of a chromosome.



Insertion. Insertion means that a number of nucleotides have been erroneously added to the genome, most often during the process of DNA replication. This number can be as small as a single nucleotide or up to thousands or even millions of nucleotides. The effect of an insertion likewise varies. Some may cause no effect at all, whereas others, even single nucleotide insertions, can completely disrupt the function of a gene and lead to a pathogenic variant associated with a genetic disease.

Leslie Biesecker
Leslie G. Biesecker, M.D.

Director & NIH Distinguished Investigator

Center for Precision Health Research