[Rearrangement of the proto-oncogene c-myc in fresh cells from Burkitt's leukemia (L3)].

The presence of a rearrangement of the proto-oncogene c-myc was investigated in the DNA of fresh cells isolated from the blood of two patients with Burkitt's leukemia (L3), and from the node biopsy of a patient with Burkitt's lymphoma. Both samples from the L3 leukemia patients had the characteristic t(8;14) translocation, while the lymphoma specimen presented no abnormality of chromosome 8. Only one of the leukemic DNA's presented a rearranged c-myc pattern, with the breakpoint region located between the first and the second exon. The c-myc pattern of the two other patients appeared normal. The finding of a rearranged c-myc oncogene in fresh cells from a Burkitt's leukemia is direct evidence for the implication of c-myc in the disease whereas most of the rearrangements previously described have been found in cell lines established in culture.