title: Translocation (2;8)(p12;q24) associated with a cryptic t(12;21)(p13;q22) TEL/AML1 gene rearrangement in a child with acute lymphoblastic leukemia.
abstract: We report a case of childhood acute lymphoblastic leukemia with the simultaneous occurrence of a t(2;8)(p12;q24) typically associated with mature B cell or Burkitt leukemia, and a t(12;21)(p13;q22) exclusively associated with pre-B cell ALL. The lymphoblasts were characterized as L2 morphology by the French-American-British classification. However, there were atypical morphologic findings for L2 ALL, including vacuolization in some cells. The lymphoblasts were periodic acid-Schiff positive and myeloperoxidase negative. Immunophenotypic analysis revealed that the majority of lymphoblasts were TdT+, CD10+, CD19+, CD20-, and cytoplasmic mu+. These features were consistent with an immature pre-B cell leukemia phenotype with some characteristics of a mature B-cell leukemia. A t(2;8)(p12;q24)(p12;q24), characteristic of mature B-cell leukemia or Burkitt type leukemia, was detected by conventional cytogenetics with no other cytogenetic abnormalities. However, diagnostic peripheral blood and bone marrow specimens demonstrated simultaneous occurrence of a cryptic t(12;21)(p13;q22) by both FISH and RT-PCR. The simultaneous occurrence of these translocations in a pediatric patient have implications for the pathogenesis of leukemias with t(2;8)(p12;q24) as well as t(12;21)(p12;q22). Analysis of additional cases of leukemia with translocations involving the MYC locus on 8q24 will be required to determine the frequency of association with the cryptic t(12;21)(p13;22), and the prognostic significance of the simultaneous occurrence of the translocations.
authors: Division of Hematology-Oncology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors: M L
authors: ML
authors: Loh
authors: Y
authors: Y
authors: Samson
authors: E
authors: E
authors: Motte
authors: L A
authors: LA
authors: Moreau
authors: V
authors: V
authors: Dalton
authors: S
authors: S
authors: Waters
authors: S E
authors: SE
authors: Sallan
authors: D G
authors: DG
authors: Gilliland
mesh_terms: D001483:Base Sequence; D002675:Child, Preschool; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics*; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D050676:Core Binding Factor Alpha 2 Subunit; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000473:pathology; D017422:Sequence Analysis, DNA; D014178:Translocation, Genetic; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D018076:DNA, Complementary; D015514:Oncogene Proteins, Fusion; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein