indel

genetics

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 20, 2026

Quick Summary

An indel is a type of genetic marker that involves the insertion or deletion of a DNA sequence. This variation can occur within a gene and is a form of polymorphism, meaning it creates different forms within a population.1

Indels are one of the most common types of genetic markers found in the human genome, alongside single nucleotide polymorphisms (SNPs) and short tandem repeats (STRs). They are caused by mistakes during DNA replication or by DNA damage.12

When an indel occurs, it can alter the DNA sequence, potentially leading to changes in protein synthesis and function. This makes indels useful for identifying individuals, populations, or species, and for locating genes associated with inherited diseases.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

1000 Genomes Project
…less common, variants known as indels, which are insertions or deletions of DNA segments of varying size occurring at virtually any location in the genome. A number of known SNPs and indels have been implicated in human health and disease and are thought to be significant for understanding human ancestry…
Read More
…less common, variants known as indels, which are insertions or deletions of DNA segments of varying size occurring at virtually any location in the genome. A number of known SNPs and indels have been implicated in human health and disease and are thought to be significant for understanding human ancestry…
Read More