Karyotype evolution in a case of chronic myelogenous leukemia with an unusual Philadelphia chromosome translocation, t(4;22), and an additional translocation, t(3;5).

A patient with chronic myelogenous leukemia was found, at the time of diagnosis, to have an unusual Philadelphia chromosome translocation, t(4;22) (q35;q11) and an additional previously unreported translocation, t(3;5) (q27;q22). The blastic crisis, which occurred after 14 months, was characterized by the appearance of i(17q). Ten months later, two different hyperdiploid cell lines with 50 chromosomes were found in about 20% of the metaphases examined.