N-ras gene point mutations in Brazilian acute myelogenous leukemia patients correlate with a poor prognosis.

The frequency of ras gene mutations varies from 11 to 27% in AML populations from the United States and Europe but it seems that there is no study regarding the frequency of mutated N-ras gene in patients with AML in South America. In order to study the frequency of N-ras gene mutations (exons 1 and 2) in Brazilian patients with AML and to evaluate the possible correlation between the presence of the mutation and clinical features, 40 patients were analyzed. N-ras mutations were identified in DNA samples from eight of 40 AML patients (20%). No significant correlation was found between N-ras mutation and age, sex, race, response to therapy, FAB subtype or occupational exposure. However, the overall survival and AML-free survival were significantly shorter in patients with N-ras mutations than in those without these abnormalities.