Genetic lesions in preleukemia.

The incidence of genetic abnormalities have been investigated in a variety of preleukaemic states RAS and FMS oncogene, p53 suppressor gene mutations and monoclonality in myelodysplastic syndromes (MDS), a paradigm for pre-leukemias have been observed. Other patients at risk of developing either secondary leukaemia or evolving into leukaemia have been similarly studied including haematologically normal patients in remission from lymphoma. Time from treatment to detection of genetic abnormalities is a significant factor in some of these patients which is consistent with the expansion of an abnormal clone. A case of non-dysplastic MDS has been identified with a 7q-karyotypic abnormality typical of therapy related MDS, abnormal progenitor growth and RAS mutations but with normal clinical features. Normal individuals have also been under investigation and found to have a low incidence of proto-oncogene mutations. A prospective study should enable us to determine if these parameters are indeed prognostic indicators.