[Molecular analysis in Argentinian patients with Burkitt's lymphoma]

Burkitt's lymphoma (BL) is a B-cell neoplasm that occurs in children throughout the world. Two distinct entities of this disease have been recognized: endemic BL (eBL), described in equatorial Africa, and sporadic BL (sBL), described in the USA and Europe. There are striking differences in the incidence, epidemiology, clinical presentation and molecular characteristics of the tumour cells between the two forms, although all BL carry identical specific chromosomal translocations. We have examined the position of the chromosomal breakpoints in the t (8;14) translocation, characteristic of this tumour, relative to the c-myc oncogene in chromosome 8, and the immunoglobulin heavy chain (IGH) locus in chromosome 14 in samples obtained from four Argentine patients using the Southern blot technique. DNA from the tumours was digested with specific enzymes and hybridized with DNA probes from the c-myc (first and third exons) and IGH locus (C mu, S mu and JH). Our analysis shows that all tumours carried the t (8;14) as shown by clonal rearrangements of c-myc in DNA treated with the enzymes Hind III and Eco RI. Moreover, all 4 tumours had chromosome 8 breakpoints within the Hind III restriction fragment that spans the gene. In case 1 it was between the Hind III and Pst I sites 5' to the first exon, in cases 2 and 4 between the Pvu II and Sma I sites 5' to the first exon and in case 3 within the first exon (Sma I-Pvu II segment).(ABSTRACT TRUNCATED AT 250 WORDS)