Genome architecture catalyzes nonrecurrent chromosomal rearrangements

Am J Hum Genet. 2003 May;72(5):1101-16. doi: 10.1086/374385. Epub 2003 Mar 20.


To investigate the potential involvement of genome architecture in nonrecurrent chromosome rearrangements, we analyzed the breakpoints of eight translocations and 18 unusual-sized deletions involving human proximal 17p. Surprisingly, we found that many deletion breakpoints occurred in low-copy repeats (LCRs); 13 were associated with novel large LCR17p structures, and 2 mapped within an LCR sequence (middle SMS-REP) within the Smith-Magenis syndrome (SMS) common deletion. Three translocation breakpoints involving 17p11 were found to be located within the centromeric alpha-satellite sequence D17Z1, three within a pericentromeric segment, and one at the distal SMS-REP. Remarkably, our analysis reveals that LCRs constitute >23% of the analyzed genome sequence in proximal 17p--an experimental observation two- to fourfold higher than predictions based on virtual analysis of the genome. Our data demonstrate that higher-order genomic architecture involving LCRs plays a significant role not only in recurrent chromosome rearrangements but also in translocations and unusual-sized deletions involving 17p.

Publication types

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

MeSH terms

  • Centromere / genetics
  • Chromosome Breakage / genetics*
  • Chromosomes, Human, Pair 17 / genetics*
  • Genome*
  • Humans
  • In Situ Hybridization, Fluorescence / methods
  • Physical Chromosome Mapping
  • Repetitive Sequences, Nucleic Acid
  • Sequence Deletion / genetics*
  • Translocation, Genetic / genetics*