Cytogenetic profile of childhood and adult megakaryoblastic leukemia (M7): a study of the Groupe Français de Cytogénétique Hématologique (GFCH).

To draw the cytogenetic profile of childhood and adult acute megakaryoblastic leukemia (M7), the Groupe Français de Cytogénétique Hématologique collected 53 cases of M7 (30 children and 23 adults). Compared to other acute myeloid leukemias, M7 is characterized by a higher incidence of abnormalities, a higher complexity of karyotypes, and a different distribution of abnormalities among children and adults. Nine cytogenetic groups were identified: normal karyotypes (group 1), patients with Down syndrome (group 2), numerical abnormalities only (group 3), t(1;22)(p13;q13) or OTT-MAL transcript (group 4), t(9;22)(q34;q11) (group 5), 3q21q26 (group 6), -5/del(5q) or -7/del(7q) or both (group 7), i(12)(p10) (group 8), and other structural changes (group 9).