CODON 12 RAS MUTATIONS IN PATIENTS WITH MYELODYSPLASTIC SYNDROME - INCIDENCE AND PROGNOSTIC VALUE

To determine the prevalence of activated ras-oncogenes (N-ras, Harvey- ras Kirsten-ras), DNA derived from peripheral blood of 51 patients wit h myelodysplastic syndrome (MDS) was investigated, The method was base d on the polymerase chain reaction (PCR) technique to amplify DNA, fol lowed by restriction fragment length polymorphism (RFLP) analysis, Amo ng the French-American-British (FAB) subtypes, N-ras mutations were fo und in two patients with refractory anemia with excess of blasts (RAEB ), in one patient with refractory anemia with excess of blasts in tran sformation (RAEB-t), and in two patients with chronic myelomonocytic l eukemia (CMML). MDS patients with a mutation at codon 12 of the N-ras gene showed shorter survival duration than other MDS patients of the s ame FAB subtypes, although these findings proved to be not statistical ly significant (P > 0.1). Interestingly, all but one patient with N-ra s mutation developed acute myelogenous leukemia (AML). In conclusion, the presence of mutation at codon 12 of the N-ras gene might serve as a negative prognostic factor at diagnosis of MDS.