DNA Fingerprinting Analysis: Methodology and Its Applications

In the early 1980s, a new type of DNA element was described that consisted of arrays of tandemly repeated short sequence units of 9–64 bp (reviewed in ref. 1 ). A large number of these arrays have subsequently been discovered. These have become known as minisatellites (by analogy with much larger satellite sequences) (2 ), and are also known as VNTRs (variable number tandem repeats) (3 ). Many minisatellites display a high degree of allelic variation in the number of repeats in the array, which is detectable as length polymorphisms in Southern blots; these minisatellites are often referred to as HVRs (hypervariable regions). The degree of heterozygosity at HVR loci is high (>99% for some HVRs), and thus, such hypervariable minisatellite loci provide highly informative genetic markers ideal for linkage analysis in humans.