A novel chromosomal abnormality t (9;14)(p24;q13) in B-acute lymphoblastic leukemia.

Acute lymphoblastic leukemia is a malignant disease of the bone marrow in which early lymphoid precursors proliferate and replace the normal hematopoietic cells of the marrow. We describe the clinical, morphologic, immunophenotypic and cytogenetic findings in the case of a 26‑year‑old man with B‑lymphoblastic leukemia. Surface marker analysis revealed that they are positive for CD markers CD10, CD19, CD13, CD34, CD45 and HLA‑DR, but negative for CD20, CD33, CD117 and CD11C markers. Cytogenetic analysis established a novel translocation, t (9;14)(p24;q13). Apart from this, spectral karyotyping revealed an additional translocation, t (6p; 14q). This is the first documented case of B‑lymphoblastic leukemia with concurrent occurrence of both abnormalities. Further studies are needed to understand the role of this abnormality in carcinogenesis.

Comparison between Conventional Cytogenetics and Interphase Fluorescence in situ Hybridization (FISH) for Patients with Multiple Myeloma

BACKGROUND: For patients with multiple myeloma (MM), different strategies are used to detect chromosomal abnormalities (CA). There have been a few studies that have directly compared FISH with conventional cytogenetics (CC) for the detection of CA. In this study, we employed a combined approach of metaphase cytogenetics and interphase FISH to investigate the genetic basis for the great heterogeneity observed in the clinical behavior of 28 MM patients. METHODS: Cytogenetic analysis was performed via traditional metaphase karyotype analysis. The FISH studies were done using DNA probes to detect translocations involving the immunoglobulin heavy chain gene (IGH) at 14q32 and deletions of 17p13.1 and 13q14. RESULTS: CA were detected by CC in 16 patients (57.1%) and by FISH in 14 patients (50.0%) of the 28 patients we studied. 14q32 abnormalities and deletion abnormalities of 13q14 and 17p13.1 were detected by CC in five patients (17.9%), three patients (10.7%) and no patients (0%), respectively and these were detected by FISH in 12 (42.8%), four (14.3%) and five (17.8%), respectively, of the 28 patients we studied. The median follow-up timefor the patients was 23.85 months (range: 0.3~58.13 months). On the univariate and multivariate analyses, none of the abnormalities detected by cytogenetics and interphase FISH affected survival. CONCLUSION: On comparing the cytogenetics and interphase FISH results, we can suggest that both studies should be an essential part of the workup for the diagnosis of patients with MM. Also, both studies may complement each other to predict the prognosis.

Why Should FISH Be Done in Patients with Acute Leukemias to Detect MLL Translocation? / 대한임상병리학회지

BACKGROUND: Translocations involving the MLL gene on the long arm of chromosome 11 (11q23) are frequently observed in acute leukemia. The detection of this genetic change has a unique significance due to its implication for poor prognosis. The aim of this study was to determine the utility of fluorescence in situ hybridization (FISH) method in detecting the MLL translocation. METHODS: We applied both conventional cytogenetic analysis (CC) and MLL FISH on 289 consecutive Korean patients (children and adults) with acute leukemia and analyzed the data, placing an emphasis on the discrepancies in the results. RESULTS: Twenty-two of 289 patients (7.6%) had the 11q23/MLL translocation. In 9 cases of 22 (41%), only FISH detected the translocation. In 8 among 22 patients, a total of 19 follow-up examinations were performed, of which FISH detected a significant level of leukemia cells harboring the MLL translocation in 5 (26%) without cytogenetic evidence. Besides the MLL translocation, FISH detected submicroscopic amplification, partial deletion of the MLL gene, and trisomy 11 in 12 cases without cytogenetic evidence. CONCLUSIONS: These results demonstrate that up to 41% of the MLL translocations at initial workups and 26% during follow-up were detected by FISH without cytogenetic evidence. Thus, we recommend that MLL FISH should be performed in the diagnosis and monitoring of acute leukemia in combination with CC.