A new translocation, t(2;4;12)(p21;q12;p13), in CD7-positive acute myeloid leukemia: a variant form of t(4;12).

We describe a 41-year-old man with CD7-positive acute myeloid leukemia (AML-M0) with trilineage-myelodysplasia. Chromosome analysis of the bone marrow cells showed 46.XY.t(2;4;12) (p21;q12;p13). Cytological and clinical features of our case were quite similar to those of AML with t(4;12)(q11-12;p13). The karyotypic interpretation was confirmed by fluorescence in situ hybridization (FISH) by using the whole-chromosome painting probes specific for chromosomes 2, 4, and 12. FISH analysis with the use of the YAC 936e2 probe, which covers the TEL gene, did not show the split signal, suggesting that a gene other than TEL was involved in the leukemogenesis of the present case. Our case with AML with t(2;4;12)(p21;q12;p13) appears to be the first case of a variant type of AML with t(4;12) (q11-12;p13).