ACUTE LEUKEMIAS EXPRESSING P210-TYPE AND P190-TYPE BCR ABL MESSENGER-RNAS - REPORT OF 2 CASES AND REVIEW OF THE LITERATURE/

We report two patients with acute leukemias who expressed two types of bcr/abl mRNA. The first case was an 8-year-old boy with acute mixed l eukemia in whom the Ph(1) chromosome and p210/p190 types of bcr/abl mR NAs were detected at diagnosis. The second case was a 39-year-old male with acute nonlymphocytic leukemia transformed from myelodysplastic s yndrome (refractory anemia with excess of blasts). In the latter case, the p210-type mRNA appeared after leukemic transformation, and the p1 90-type transcript was detected only during the late stage when the Ph (1) chromosome was first observed. The leukemias in these two patients were aggressive in their clinical courses. We conclude that the dual expression of p210 and p190 types of bcr/abl is a factor indicating a poor prognosis, and that, in some patients, p190-type bcr/abl may cont ribute to disease progression.