ABSTRACT
Acute Myeloid Leukemia (AML) is a heterogeneous disease with respect to morphology, immunophenotype, chromosomal abnormalities and genetic lesions. While a majority of AML cases harbour recurrent chromosomal abnormalities, several rare, apparently unique or novel aberrations may be identified by conventional cytogenetics. In fact, with the prognostic relevance of chromosomal abnormalities, and with the advent of new-age, target-specific therapy, identifying such aberrations becomes vital. In this study, we present a case of pediatric AML with ins(19;X)(q13.1;p11.2q28) and t(1;11)(q10;p10), both, novel, previously unreported chromosomal abnormalities in AML. Post induction, both these clonal cytogenetic abnormalities persisted. The documentation of this case will help determine the significance of these cytogenetic abnormalities. Also, this case exemplifies the importance of cytogenetics in the complete characterization and risk stratification of AML patients.
Subject(s)
Chromosome Inversion , Cytogenetic Analysis , Translocation, Genetic , Child , Female , Follow-Up Studies , Humans , KaryotypeABSTRACT
Ploidy, besides known translocations in lymphoblasts, is a strong predictor of prognosis in B- cell progenitor acute lymphoblastic leukemia (BCP-ALL). While hyperdiploidy with >50 chromosomes shows a favourable outcome, hypodiploidy with <45 chromosomes have a dismal clinical outcome. However, there exists a small subset where both the hypodiploid and hyperdiploid clones are apparent either by cytogenetics or flow cytometry and are defined partially masked hypodiploids or mosaics based on the percentage of clonal population. These patients are essentially hypodiploids, and show the hyperdiploid clone as a consequence of endoreduplication of the primary hypodiploid clone- A phenomenon of successive replication of genome without mitosis (cytokinesis) resulting in increased ploidy. In the current study, we present the complete clinical, hematological and cytogenetic profile of 11 such newly diagnosed mosaics or partially masked hypodiploid BCP-ALL cases.
Subject(s)
Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/genetics , Adolescent , Adult , Child , Child, Preschool , Cytogenetic Analysis , Endoreduplication , Female , Humans , Male , Ploidies , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/diagnosis , Prognosis , Translocation, Genetic , Young AdultABSTRACT
OBJECTIVES: B-cell acute lymphoblastic leukemia is the clonal proliferation of B-lymphoblasts, primarily in the blood and bone marrow. The morphology of these cells is largely of L1 or L2 type according to French-American-British (FAB) classification. Molecular cytogenetic testing remains the gold standard technique for genetic classification of ALL along with molecular tests. Here we describe a case of pediatric B-ALL with dic(7;9)(p11.1;p11.1) and deletion of CUL1 (7q36) as a primary abnormality. Although both 7p and 9p deletions are associated with poor prognosis, the patient responded well to standard risk induction therapy. The abnormalities were identified by conventional karyotype and fluorescence in situ hybridization. Response to treatment was assessed by monitoring minimal residual disease.
