Barbara Kaiser-McCaw

Ataxia-pancytopenia: Syndrome of cerebellar ataxia, hypoplastic anemia, monosomy 7, and acute myelogenous leukemia

In a family with ataxia and pancytopenia, the proband had cerebellar ataxia, developed hypoplastic anemia at age 3 years, and died of acute myelomonocytic leukemia at age 7. Serial cytogenetic studies of the probands hypoplastic bone marrow over a 25-month period revealed progressive expansion of a clone of cells with C(6 - 12 + X) monosomy from 33% to 94% of metaphases. The missing chromosome by banding was deduced to be No.7. No increased sensitivity of the patients cells was found in response to ultraviolet or ionizing radiation or to mitomycin C. Cerebellar atrophy was confirmed at autopsy. Family studies revealed cerebellar ataxia in the probands father and all four siblings. Two brothers, including one with C-monosomy, died with hypoplastic anemia and another brother died with acute myelocytic leukemia. The only surviving sibling is a 19-year-old sister who has unexplained anemia, decreased mitotic activity in bone marrow, and slow progressive cerebellar ataxia. The name ataxia-pancytopenia syndrome is proposed to encourage study of additional patients with this disorder, which predisposes to pancytopenia and acute leukemia.

Acute myeloblastic leukemia (AML) with t(6;9) (p23;q34): A specific subgroup of AML?

A case of acute myeloblastic leukemia (AML) of M2 type in the FAB classification without Auer bodies in the leukemic cells was shown to have t(6;9)(p23;q34) in the marrow cells. Four hematologically similar cases with identical karyotype changes have been published. We propose, in support of others, that this may constitute a subgroup of AML characterized by a translocation between chromosome #6 and #9.

Complex cytogenetic findings in acute leukemia

Although certain types of acute nonlymphocytic leukemia (ANLL) are now characterized by specific chromosome translocations, certain other cases of ANLL elude simple cytogenetic classification. We describe here a case of acute myelomonocytic leukemia with a complex and unusual karyotype picture including double minutes, three definite translocations, two other possible translocations, and additional morphologic and numerical chromosome changes. The three definite translocations were t(2;11), t(2;12), and t(5;15), fitting the criteria of major karyotype abnormalities. These complex and unusual chromosome findings may relate to the rapid course of the disease.