title: Nonrandom distribution of exchange points in patients with structural rearrangements.
abstract: High resolution studies of structural rearrangements were carried out using the G-band technique. A total of 220 breakage points were identified within individual bands from 117 unrelated cases born with a structural rearrangement. Breakage points were not evenly distributed along chromosomes in terms of G-band patterns. There was an excess involvement of light bands and a striking lack of dark bands in both reciprocal translocations and inversions. In reciprocal translocations, the middle part of a chromosome arm has less chance of being the site of an exchange than the terminal and centromeric parts. The implications of these results are briefly discussed.
mesh_terms: D002842:Chromatids / Q000502:physiology / Q000648:ultrastructure*; D002869:Chromosome Aberrations; D007446:Chromosome Inversion; D003434:Crossing Over, Genetic; D006801:Humans; D014178:Translocation, Genetic