Evolutionarily conserved low copy repeats (LCRs) in 22q11 mediate deletions, duplications, translocations, and genomic instability: an update and literature review

Genet Med. 2001 Jan-Feb;3(1):6-13. doi: 10.1097/00125817-200101000-00003.


Several constitutional rearrangements, including deletions, duplications, and translocations, are associated with 22q11.2. These rearrangements give rise to a variety of genomic disorders, including DiGeorge, velocardiofacial, and conotruncal anomaly face syndromes (DGS/VCFS/CAFS), cat eye syndrome (CES), and the supernumerary der(22)t(11;22) syndrome associated with the recurrent t(11;22). Chromosome 22-specific duplications or low copy repeats (LCRs) have been directly implicated in the chromosomal rearrangements associated with 22q11.2. Extensive sequence analysis of the different copies of 22q11 LCRs suggests a complex organization. Examination of their evolutionary origin suggests that the duplications in 22q11.2 may predate the divergence of New World monkeys 40 million years ago. Based on the current data, a number of models are proposed to explain the LCR-mediated constitutional rearrangements of 22q11.2.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Abnormalities, Multiple / genetics
  • Animals
  • Chromosome Aberrations
  • Chromosome Deletion
  • Chromosomes, Human, Pair 22*
  • Gene Amplification
  • Gene Deletion*
  • Gene Dosage
  • Gene Duplication*
  • Humans
  • Models, Genetic
  • Phylogeny
  • Repetitive Sequences, Nucleic Acid*
  • Syndrome
  • Translocation, Genetic*