Frequent association between trisomy 15 and t(8;21)(q22;q22) in acute myeloid leukemia

Duplication and triplication of der(21)t(8;21)(q22;q22) in acute myeloid leukemia

We report on two patients with complicons resulting in duplication der(21)t(8;21)(q22;q22), triplication in the form of isochromosome of der(21)t(8;21), and four copies of ETO-AML1 fusion. Duplication of der(21) was present at diagnosis as a minor cell population in one patient, while the presence of isoderivative (21)t(8;21) characterized the relapse cells of the second patient. Due to the rarity of these cases, literature search of other reported cases of complicons may be taken as evidence that duplication and triplication of ETO-AML1 may be a poor prognostic indicator, regardless of whether it is present at diagnosis or relapse.

Duplication 15q as the sole anomaly in an acute promyelocytic leukemia patient without t(15;17)

We present a unique chromosomal abnormality found in a patient with acute myeloblastic leukemia of French-American-British subtype M3. The patient was referred for an evaluation of a chromosomal anomaly exclusively associated with FAB M3 or acute promyelocytic leukemia: a translocation between chromosomes 15 and 17, t(15;17)(q22;q21.1). Neither t(15;17) nor rearrangement of RARalpha was detected by routine G-banded chromosome as well as fluorescence in situ hybridization analysis using the commercial dual-color PML/RARalpha translocation probe and the RARalpha probe, a break apart rearrangement dual-color probe. Instead of the typical rearrangement between chromosomes 15 and 17, all cells analyzed had a duplication of the segment of chromosome 15 between bands 15q15 and 15q26.

Duplication 15q in a patient with t(8;21) acute myeloblastic leukemia (M2)

We present unique chromosomal abnormalities found in a patient with acute myeloblastic leukemia (AML) of French-American-British subtype M2. The patient was referred for an evaluation of chromosomal anomaly associated with AML. She was found to have an abnormal karyotype 46,XX,t(8;21)(q22;q22), and a questionable dup(15)(q15q22) in the majority of cells analyzed. Two cells had the same chromosomal anomalies plus a duplicated derivative chromosome 21 [der(21)t(8;21)(q22;q22)]. These cytogenetic findings were confirmed by fluorescence in situ hybridization utilizing the appropriate DNA probes. To our knowledge, this is the first case report of a combination of the translocation between chromosomes 8 and 21, a duplication of chromosome 15 [dup(15)(q15q22), and a duplicated derivative chromosome 21 [der(21)t(8;21)(q22;q22)].