Chromosomal translocation t(1;22) and sis oncogene variant with gene amplification in a case of atypical malignant lymphoma.

sis Oncogene amplification and PstI restriction enzyme variant were found in a patient of atypical malignant lymphoma with chromosomal translocation t(1;22). A diagnosis of atypical malignant lymphoma was made because dual rearrangements of both beta chain of T-cell receptor gene and heavy and kappa chains of immunoglobulin genes were observed by DNA analysis extracted from the lymph node. Amplification of sis was estimated to be about fivefold by dot blot. BamHI and EcoRI digested DNA hybridized with sis probe from blood and lymph nodes revealed identical bands. Lymph node DNA digested with PstI showed an extra band when compared with DNA samples extracted from peripheral blood. Other oncogenes, such as myb, abl, and myc showed no variant or amplification. These findings suggest that sis is abnormally rearranged in this lymphoma. One possible role of genes on chromosome 22, including sis oncogene, in the pathogenesis of this atypical malignant lymphoma is discussed.