Homogeneously staining chromosomal region in a case of erythroleukaemia

Cytogenetical analysis of bone marrow and peripheral blood cells in a case of erythroleukaemia revealed a complex karyotype with a stemline of 44 chromosomes. I marker chromosome bearing a homogeneously staining region (hsr) was found in each of the aneuploid cells examined. The hsr was localised to the chromosome regions 15q12 and 15p12. The possible function of amplified DNA sequences and the relationship of hsr to cell proliferation are discussed.