Males with chronic myeloid leukemia and the 45, XO, Ph1 chromosome pattern.

Two cases of chronic myeloid leukemia in which the cytogenetic clone was 45, XO, Ph(1) are described and compared with 20 cases recorded in the literature. The 45, XO line is peculiar to the leukemic cells and is not a manifestation of constitutional mosaicism. It probably arises from a 46, XY, Ph(1) line by loss of the Y chromosome. Because of the few cases reported, one cannot be certain that these men have a better prognosis, although the median survival time suggests that this is so. Infertility is not part of this disorder.