Cytogenetic and morphological findings in 166 patients with de novo acute myeloid leukemia in southern Brazil.

Chromosomal rearrangements correlate with different clinical subgroups of blood disorders. Some of these chromosomal abnormalities are found in individuals from specific geographical areas and ethnic groups. A high incidence of t(15;17) translocation has been observed, for example, in the Hispanic populations of the United States and Spain. The same occurs in South America, due to the rich diversity of ethnic groups that colonized the region. We performed a cytogenetic analysis of 166 patients at the Division of Hematology of Hospital de Clínicas de Porto Alegre between 1990 and 2002. Those patients who met the criteria for de novo acute myeloid leukemia (AML) and whose karyotypes could be successfully determined were included in the study. The karyotypes of each patient and the French-American-British (FAB) criteria for the diagnosis of AML were reviewed. Chromosomal abnormalities were identified and classified according to ISCN 1995. Chromosomal abnormalities were found in 53.6% of cases. Abnormalities were significantly more common in the FAB-M3 group (70.3%). The most common balanced translocation was t(15;17), observed in 13.25% of the patients.