Molecular diagnosis of haematological neoplasms.

DNA analysis has become of practical value in the diagnosis and classification of leukaemias and lymphomas. This is exemplified by the study of lymphoproliferative disorders using immunoglobulin and T-cell receptor gene probes for the determination of clonality and cell lineage. Chromosomal analysis with DNA probes is now a useful complementary approach to cytogenetics. For example, the study of particular lymphomas or chronic myelogenous leukaemia with DNA probes hybridising to specific chromosomal breakpoints allows the detection of chromosomal translocations at a genomic level. Chromosomal loss in neoplastic cells can be detected by DNA probes in individual heterozygous for particular restriction fragment length polymorphisms, most efficiently by locus-specific hypervariable region probles. These techniques will enable progress to be made in the understanding of the biology of remission and disease progression in haematological malignancies.