Chromosome 14 Abnormality with a Breakpoint of p12 in Adult T-cell Leukemia

We describe a patient with adult T-cell leukemia (ATL) with a 14p chromosomal abnormality. Cytogenetic study revealed two clonal populations of leukemic cells in the peripheral blood sample. Both clones were karyotypically related to each other. One of them showed rearrangement of chromosome 14 at break band p 12 (14p12) in addition to + 3, + 7, -X and del(6) (q14q21). The nucleolar organizer region (NOR) is assigned to the band 14p12 and the role of the rearrangement of chromosome 14p12 in the pathogenesis of ATL is discussed.