[Cytogenetics of the lymphomas].

A retrospective study of children and adults suffering acute leukemias was made. Among those without any antecedents of exposure to mutagenic agents, 24% showed chromosomal abnormalities. In the group of individuals exposed to mutagenic agents, 82% showed chromosomal aberrations, that were related to changes of the type -5, -7, +8 or +21 in 84% of the cases.