Acute Leukemias Expressing p210-and p190-Type bcr/ abl mRNAs: Report of Two Cases and Review of the Literature

Abstract

We report two patients with acute leukemias who expressed two types of bcr/ αbl mRNA. The first case was an 8-year-old boy with acute mixed leukemia in whom the Ph¹ chromosome and p²¹⁰/p¹⁹⁰ types of bcr/αbl mRNAs were detected at diagnosis. The second case was a 39-year-old male with acute non-lymphocytic leukemia transformed from myelodysplastic syndrome (refractory anemia with excess of blasts). In the latter case, the p²¹⁰-type mRNA appeared after leukemic transformation, and the p¹⁹⁰-type transcript was detected only during the late stage when the Ph1 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/ αbl is a factor indicating a poor prognosis, and that, in some patients, p¹⁹⁰-type bcr/αbl may contribute to disease progression.