Cytogenetic markers in detecting the effects of exposure to complex mixtures of chemicals

A significant proportion of the mutations responsible for both inherited and acquired human disease are a consequence of chromosome structural changes and of losses or gains of whole chromosomes. Some of these changes are readily detectable by the cytogeneticist and their frequencies are increased following exposure of individuals to mutagens. Techniques to visualize human sperm chromosomes and to detect micronuclei in spermatids now allow the cytogeneticist to detect induced chromosomal mutations in human germ cells. Rapid advances in our understanding of the molecular organization of the human genome, in the application of recombinant DNA probes and in situ hybridization with isotopic and non-isotopic probes, now enable chromosome organelles and specific chromosomal regions to be uniquely identified. These approaches are being applied to analyse chromosomal changes in somatic cells and, coupled with the development of machines to rapidly analyse chromosomes and nuclei, provide a powerful means to utilize cytogenetic markers to detect the effects of exposure of people to complex mixtures of chemical mutagens.