MLL partner genes in secondary acute lymphoblastic leukemia: Report of a new partner PRRC1 and review of the literature.

Secondary acute lymphoblastic leukemia (sALL) following chemotherapy and/or radiotherapy of previous malignancies represents 2–10% of all cases of ALL. A 72-year-old female patient was diagnosed with acute lymphoblastic leukemia following chemotherapy for a diffuse large B cell lymphoma. Banding cytogenetics showed a t(t(5;11)(q23–31;q23) in 20 of the 21 metaphases examined and fluorescent in situ hybridization confirmed rearrangement of MLL . Long distance inverse-polymerase chain reaction revealed an in-frame fusion between 5′ MLL and 3′ PRRC1 . Sixty-five cases of sALL associated with 11q23/ MLL rearrangement, including 47 with a t(4;11)(q21;q23), were retrieved from the literature. Drug regimen used to treat the primary neoplasm was available for 54 patients; 52 had received a topoisomerase II inhibitor, known to induce MLL rearrangement. [ABSTRACT FROM AUTHOR]