Chromosome-specific low-copy repeats (2–10+) found in various regions of the human genome, varying in size from a few kilobases in length to hundreds of kilobases. Recombination between duplicated segments can lead to deletion, further duplication, inversion, etc. and dosage imbalance caused by duplication can cause abnormalities. There appear to be two general classes of duplicons, sometimes separated by internal (TTAGGG)n-like islands; large and highly similar centromerically positioned subtelomere duplications and more abundant, dissimilar distal duplicons. More stringent definitions are used in detailed genomic analyses (e.g. >90% nucleotide sequence identity and >1 kb in size).
Subjects: Medicine and Health.