Chromosomal studies of leukemic and preleukemic Fanconii's anemia patients: examples of acquired 'chromosomal amplification.'.

Cytogenetic studies of three Fanconi's anemia patients are reported, one of the patients having erythroleukemia, the other two preleukemia. Clonal abnormalities were present in all three cases. Partial chromosomal duplication uncommon in other leukemias was observed. Partial duplication of the long arm of chromosome 3 has been observed in the present case of erythroleukemia examined as well as in a previously reported one.