DETECTION OF C-MYC ONCOGENE AMPLIFICATION IN A CML ELASTIC PHASE PATIENT WITH DOUBLE MINUTE CHROMOSOMES

Double minute chromosomes (dmin) are relatively rare in leukemias. Cyt ogenetic analysis of blood cells from a woman with blastic phase chron ic myelogenous leukemia (BC-CML) showed numerous dmin chromosomes and complex abnormalities including a Philadelphia (ph(1))-chromosome. Onc ogene amplification in hematopoietic malignancies is also rare. Using PCR, we retrospectively investigated the extent of c-myc gene amplific ation in DNA extracted from stored blood smears from the patient. To q ualify the PCR products, the beta-globin gene was used as the internal reference gene and it was co-amplified with the c-myc gene. The exten t of amplified c-myc was about 6.8-fold. This finding suggests that th e c-myc gene was amplified in dmin and that the gene amplification con tributes to the progression to acute leukemia or rapid growth of leuke mic cells.