Major karyotype aberrations, including t(3;12), in a patient with myelodysplastic syndrome.

Cytogenetic analysis of bone marrow cells was performed twice on a patient with myelodysplastic syndrome, specifically, refractory anemia with excess blasts. The patient had a progressive course, with transformation toward acute leukemia and death within 3 months. Chromosome analysis showed major karyotype abnormalities, including dir dup (1p), t(3;12), and a unique breakage of a #15 resulting in t(15;18) and dic(15;21). Involvement of #3 and #12 in a translocation has been recently reported, and a comparison with these cases is made with a discussion of the significance.