t(1;7) in acute myeloblastic leukemia following myelodysplastic syndrome (RAEB-T).

A case is described of myelodysplastic syndrome (MDS) refractory anemia type with an excess of blasts in transformation with early leukemic evolution (AML-M1). All bone marrow cells examined showed an unbalanced translocation t(1;7). The karyotype was 45, xy, -21, -7, + der dic t(1;7) (q12;q21). There are reports in the literature of the translocation t(1;7) (p11;p11), which leads to trisomy of the long arms of chromosome #1 and monosomy of the long arms of chromosome #7. In the case here described the breakpoints of the chromosomes involved in the translocation differ from the classic ones: in this case there is trisomy of the region 1q12----1qter and monosomy of the region 7q21----7qter. Some clinical and cytogenetic considerations are suggested.