Overexpression of the PRAD1 oncogene in a patient with prolymphocytic leukemia with t(11;14)(q13;q32).

Prolymphocytic leukemia (PLL) was diagnosed by morphologic and immunophenotypical studies in a 72-year-old Japanese man. Massive splenomegaly was present but lymphadenopathy was minimal in this case. Chromosomal analysis of peripheral mononuclear cells showed t(11;14)(q13;q32) in all metaphases examined, except for one normal karyotype. Northern blot analysis of RNA prepared from leukemic cells obtained from the patient revealed overexpression of the PRAD1/cyclin D1 proto-oncogene, which has not been described previously in patients with PLL.