Extensive cytogenetic studies of clonality following interferon-alpha therapy in chronic myeloid leukemia occurring in monosomic cells in a patient with Turner syndrome mosaic

Rare cytogenetic abnormalities in myelodysplastic syndromes

The karyotype represents one of the main cornerstones for the International Prognostic Scoring System (IPSS) and the revised IPSS-R (IPSS-R) that are most widely used for prognostication in patients with myelodysplastic syndromes (MDS). The most frequent cytogenetic abnormalities in MDS, i.e. del(5q), -7/del(7q), +8, complex karyotypes, or -Y have been extensively explored for their prognostic impact. The IPSS-R also considers some less frequent abnormalities such as del(11q), isochromosome 17, +19, or 3q abnormalities. However, more than 600 different cytogenetic categories had been identified in a previous MDS study. This review aims to focus interest on selected rare cytogenetic abnormalities in patients with MDS. Examples are numerical gains of the chromosomes 11 (indicating rapid progression), of chromosome 14 or 14q (prognostically intermediate to favorable), -X (in females, with an intermediate prognosis), or numerical abnormalities of chromosome 21. Structural abnormalities are also considered, e.g. del(13q) that is associated with bone marrow failure syndromes and favorable response to immunosuppressive therapy. These and other rare cytogenetic abnormalities should be integrated into existing prognostication systems such as the IPSS-R. However, due to the very low number of cases, this is clearly dependent on international collaboration. Hopefully, this article will help to inaugurate this process.

Leukemias associated with Turner syndrome: Report of three cases and review of the literature

Cases of leukemia associated with Turner syndrome (TS) are rare. Here we report three TS patients with leukemia including one case of T-large granular lymphocyte leukemia (T-LGL), one rare case of coexistence of chronic lymphocytic leukemia (CLL) and idiopathic myelofibrosis (IMF) and one case of a patient with AML-M2 who received autologous stem cell transplantation (SCT). T-LGL and coexistence of CLL and IMF associated with TS are reported for the first time while the last case represents the first report of SCT in a leukemia patient with TS. Our cases and the limited data of previously reported leukemia patients with TS suggest that TS is not associated with a specific type of leukemia and that presentation, clinical course and response to treatment are similar to that of the non-TS leukemia patients. However, these patients may have a higher risk of liver complications. Interestingly, in the mosaic TS patients, the abnormal clones were restricted to the monosomic 45,X cells, indicating that the leukemic clones possibly originate from the monosomic cell line. Even in cases with no additional chromosome abnormalities, the ratio of X/XX cells in bone marrow cells was significantly increased compared to that in constitutional karyotype, indicating that monosomic cells possibly provide a survival advantage for leukemia cells or that reduced programmed cell death may be responsible for the expansion of the monosomic cells.

A case of Turner syndrome associated with acute myeloid leukemia (M2)

A 9-year-old girl was diagnosed as acute myeloid leukemia-M2 according to the French-American-British classification. In addition, a diagnosis of Turner syndrome (TS) was made, on the basis of the presence of the chromosomal abnormality, ovarian failure, and abnormal physical features. In particular, children with Down syndrome have increased risk of developing acute myeloblastic leukemia especially M7. On the other hand, cases of myeloid leukemia that are complicated with TS are extremely rare. This is the first report of TS with acute myeloid leukemia of M2 subtype and t (8; 21) in children.

Limited clinical value of regular bone marrow cytogenetic analysis in imatinib-treated chronic phase CML patients monitored by RQ-PCR for BCR-ABL

Real-time quantitative polymerase chain reaction (PCR) for BCR-ABL mRNA in the peripheral blood (RQ-PCR) provides an accurate and reliable measure of response to therapy in chronic myeloid leukaemia (CML). We wanted to determine in what circumstances additional clinically relevant information was provided by simultaneous cytogenetic analysis in RQ-PCR monitored patients receiving imatinib treatment. We analysed 828 simultaneous RQ-PCR and bone marrow cytogenetic analyses from 183 patients with chronic phase CML with a median follow-up of 20 months. Cytogenetic progression was defined as Philadelphia (Ph)-positive clonal evolution, loss of complete cytogenetic response or an increase of > or = 20% Ph-positive cells. Cytogenetic progression occurred in 24/183 (13%) patients. At the time of cytogenetic progression, none of the 24 patients had a major molecular response (MMR; > or = 3-log reduction in BCR-ABL from standardised baseline). There were 320 RQ-PCR results from 95 patients indicating MMR. No abnormality was detected in any of the corresponding cytogenetic analyses. A policy of regular RQ-PCR monitoring with cytogenetic analysis targetted only to patients who have not achieved, or have lost MMR would represent a rational approach to monitoring and spare most patients the discomfort of multiple marrow aspirates. This approach depends upon availability of an accurate, reproducible RQ-PCR assay with ongoing quality assurance.

Constitutional chromosome aberrations as pathogenetic events in hematologic malignancies

A predisposition to tumor development is associated with some constitutional chromosomal abnormalities. Investigations of families with an apparent hereditary cancer and constitutional chromosome rearrangements have led to the molecular identification of tumor suppressor genes. Under the somatic mutation theory for the development of cancer, two mutational events are required. The first step may be a constitutional event and the second an acquired genetic mutation. Cytogenetic studies were performed on 5633 bone marrow specimens from patients with hematologic malignancies from a single institution. Fifty cases of constitutional chromosome aberrations were detected. Data collected from the literature and from our series are reviewed and compared with the incidence of specific constitutional chromosome aberrations in the newborn population. Possible mechanisms that may predispose individuals with constitutional chromosome aberrations to the development of a hematologic malignancy are reviewed.