Translocation (Y;1)(q12;q21) in acute leukemia

RABGAP1L gene rearrangement resulting from a der(Y)t(Y;1)(q12;q25) in acute myeloid leukemia arising in a child with Klinefelter syndrome

In this study, we report the molecular cytogenetic characterization of an acute myeloid leukemia with a der(Y)t(Y;1)(q12;q25) in bone marrow cells in a child with Klinefelter syndrome. Conventional cytogenetics demonstrated the unbalanced translocation, i.e., a trisomic 1q25-qter juxtaposed to Yq12 replaced the terminal segment of chromosome Y was acquired and present only on bone marrow cells. Fluorescence in situ hybridization showed that the breakpoint at 1q25 disrupted RABGAP1L, a strongly expressed gene in CFU-GEMM, erythroid cells, and megakaryocytes, while the Yq12 breakpoint fell within the heterochromatic region. As der(Y)t(Y;1)(q12;q25) was an isolated cytogenetic change, RABGAP1L rearrangement as well as gene(s) dosage effects correlated to 1q25-qter trisomy, and Yq12-qter loss may make a major contribution to leukemogenesis and/or disease progression.

Spectral karyotyping refined the identification of a der(Y)t(Y;1)(q11.1 or.2;q12) in the blast cells of a patient with atypical chronic myeloid leukemia

We report a case of atypical chronic myeloid leukemia who showed leukocytosis with immature granulocytes and dysplastic features but no monocytosis or basophilia. Cytogenetic analysis by conventional G-banding showed an abnormal clone, which was interpreted as 46,X,-Y,+der(?)t(?;1)(?;q?1), and no Philadelphia chromosome. Reverse transcription-polymerase chain reaction did not show either major or minor BCR-ABL chimeric mRNA. Spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) refined the karyotype to 46,X,der(Y)t(Y;1)(q11.1 or.2;q12). The der(Y)t(Y;1) abnormality was reported previously in 9 cases and associated with myelodysplastic syndrome or chronic myeloproliferative disorders. SKY in combination with the standard banding method and FISH may be useful for exploring undefined chromosome abnormalities in hematological disorders.

Askin tumor and acute myeloid leukemia in a patient with constitutional partial Y disomy

We report the case of a young adult male carrying a constitutional unbalanced t(Y;13)(q11-12;p13) leading to a partial Y disomy, and presenting successively, in a 39-month interval, with an Askin tumor and a t(8;21) acute myeloid leukemia. The origin of the two neoplasias in this patient is discussed.

Myelodysplastic syndrome presenting with clonal rearrangement isolated to chromosomal region 1q

Myelodysplastic syndrome (MDS) is a malignant hematologic disorder that may present with clinical features consistent with the diagnosis of severe aplastic anemia (SAA). Distinguishing the two disorders may depend on the presence of a clonal chromosomal abnormality. In the following, we report a case of MDS associated with what we believe to be a previously unreported clonal abnormality of chromosome 1q, a finding that enabled us to distinguish between MDS and SAA.

Derivative (y)t(Y;1)(q12;q12),+9 in a patient with polycythemia vera during transition into myelodysplasia

Cytogenetic analysis of bone marrow cells of a 63-year-old male Caucasian patient with polycythemia vera (PV) who developed anemia, thrombocytopenia, and increased granulocytic immaturity revealed a 47, X,der(Y) t(Y;1)(q12;q12),+9 karyotype. The breakpoint in chromosome 1 appeared to map to q12 and not to q21, as has been described in previous reports without FISH confirmation. In the 4 years before this transition the patient was polycythemic and, accordingly, treated with phlebotomy and three short courses of busulfan. The cytogenetic picture observed has been described before in seven patients: three with PV, three with myelodysplasia, and one with Fanconi anemia. In 5/7 cases, like in our patient, the abnormality was observed during transition of the disease into either myelodysplasia or AML.

Translocation (Y;1)(q12;q12) in hematologic malignancies. Report on two new cases, FISH characterization, and review of the literature

Translocation (Y;1)(q12;q12) is a rare cytogenetic anomaly occurring in hematologic disorders thought to affect stem cells. We report here on two new cases, one end-stage myelofibrosis and one chronic myelomonocytic leukemia. The translocation breakpoints were assessed by conventional cytogenetic techniques in both cases and by FISH in the second case. A partial trisomy of the 1q21-qter region could be demonstrated. The data of the literature are reviewed and the possible pathogenetic mechanisms are discussed.