Non-random occurrence of 7–14 translocations in human lymphocyte cultures

SOMATIC cells dividing in vitro occasionally show chromosome recombination between non-homologues most often in situations associated with an increased frequency of chromosome breakage and reunion1,2 their occurrence being recognised by the observation of exchange figures. With the advent of new techniques for chromosome identification3 it is now possible to identify the chromosomes involved in these rearrangements and to recognise some translocations which might otherwise be missed.