Two cases of myeloid disorders and a t(8;12) (q12;p13).

BACKGROUND AND OBJECTIVE Rearrangements of the short arm of chromosome 12 have been described in different hematologic malignancies. Some of these abnormalities showed a rearrangement of the ETV6 gene. We studied the 12p region in one case with a t(8;12)(q12;p13) by fluorescence in situ hybridization (FISH). DESIGN AND METHODS We have identified a chromosome translocation, t(8;12)(q12;p13) in two patients with myeloid disorders; one with acute myelogenous leukemia (AML) and one with refractory anemia (RA). FISH studies with specific probes (cosmids and YACs) for the 12p region were used to investigate one case. RESULTS FISH studies demonstrated hemizygous loss of the ETV6 and CDKN1B regions and two copies of the CCDN2 locus, as a result of the balanced translocation and an additional copy of the der(8). INTERPRETATION AND CONCLUSIONS Myeloid diseases with t(8;12)(q12;p13) have an interstitial deletion of 12p, including the ETV6 and CDKN1B regions. A duplication of CCDN2 locus can also be found.