Minisatellites are small sequences of DNA that do not encode proteins but appear throughout the genome hundreds of times, with many repeated copies lying next to each other.
Minisatellites and their shorter cousins, the microsatellites, together are classified as VNTR (variable number of tandem repeats) DNA.
[citation needed] Hypervariable minisatellites have core units 9–64 bp long and are found mainly at the centromeric regions.
Since all hypermutable minisatellites contain internal variants, they provide extremely informative systems for analyzing the complex turnover processes that occur at this class of tandem repeat.
Somatic instability detected in blood DNA shows simple and rare intra-allelic events two to three orders of magnitude lower than in sperm.
In alternative models, it is the presence of neighbouring double-strand hotspots which is the primary cause of minisatellite repeat copy number variations.
Minisatellites were subsequently also used for genetic markers in linkage analysis and population studies, but were soon replaced by microsatellite profiling in the 1990s.