An Acute Myeloid Leukemia Patient with a t(6;20)(q13;q11.2) and an Extra Derivative Chromosome 1 Involving Chromosomes 14 and 1.

We report the case of a 50-year-old male with acute myeloid leukemia (AML). Chromosome analysis revealed an abnormal karyotype with a t(6;20)(q13;q11.2) and a complex rearrangement leading to an extra derivative chromosome 1 [der(1)(14q32->14p13::1p13->1q44] which was confirmed by metaphase FISH. FISH analysis confirmed an extra copy of 1q25 in 30.5% [61/200] of the nuclei examined. Rearrangements leading to an extra copy of 1q are common in AML, but translocations involving chromosomes 6 and 20 are rarely observed. Both were seen previously in this patient, suggesting persistence of this patient's neoplasm. Only six cases in the literature describe translocations between chromosomes 6 and 20. However, the breakpoints found in our patient [t(6;20)(q13;q11.2)] appear to be unique. Further studies need to be conducted to determine if this is a common/rare abnormality in AML. Also, there was a complex rearrangement involving chromosomes 1 and 14, which was characterized by metaphase FISH, which is still a powerful tool for detecting complex rearrangements in the clinical cytogenetics laboratory.