Minisatellite

A minisatellite (also referred as VNTR) is a section of DNA that consists of a short series of bases 10–60 bp. These occur at more than 1,000 locations in the human genome. Some minisatellites contain a central (or "core") sequence of letters “GGGCAGGANG” (where N can be any base) or more generally a strand bias with purines (adenosine (A) and guanine (G)) on one strand and pyrimidines (cytosine (C) and thymine (T)) on the other. It has been proposed that this sequence encourages chromosomes to swap DNA. In alternative models, it is the presence of a neighbouring cis-acting meiotic double-strand break hotspot which is the primary cause of minisatellite repeat copy number variations. Somatic changes are suggested to result from replication difficulties (which might include replication slippage, among other phenomena). When such events occur, mistakes are made, thus causing minisatellites at over 1,000 locations in a person's genome to have slightly different numbers of repeats, thereby making each individual unique. The most highly mutable minisatellite locus described so far is CEB1 (D2S90) described by Vergnaud.