title: Childhood pre-B cell acute lymphoblastic leukemia with translocation t(1;19)(q21.1;p13.3) and two additional chromosomal aberrations involving chromosomes 1, 6, and 13: a case report.
abstract: BACKGROUND
  The translocation t(1;19)(q23;p13), which results in the TCF3-PBX1 chimeric gene, is one of the most frequent rearrangements observed in B cell acute lymphoblastic leukemia. It appears in both adult and pediatric patients with B cell acute lymphoblastic leukemia at an overall frequency of 3 to 5%. Most cases of pre-B cell acute lymphoblastic leukemia carrying the translocation t(1;19) have a typical immunophenotype with homogeneous expression of CD19, CD10, CD9, complete absence of CD34, and at least diminished CD20. Moreover, the translocation t(1;19) correlates with known clinical high risk factors, such as elevated white blood cell count, high serum lactate dehydrogenase levels, and central nervous system involvement; early reports indicated that patients with translocation t(1;19) had a poor outcome under standard treatment.
  
  
  METHODS
  We report the case of a 15-year-old Syrian boy with pre-B cell acute lymphoblastic leukemia with abnormal karyotype with a der(19)t(1;19)(q21.1;p13.3) and two yet unreported chromosomal aberrations: an interstitial deletion 6q12 to 6q26 and a der(13)t(1;13)(q21.1;p13). According to the literature, cases who are translocation t(1;19)-positive have a significantly higher incidence of central nervous system relapse than patients with acute lymphoblastic leukemia without the translocation. Of interest, central nervous system involvement was also seen in our patient.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first case of childhood pre-B cell acute lymphoblastic leukemia with an unbalanced translocation t(1;19) with two additional chromosomal aberrations, del(6)(q12q26) and t(1;13)(q21.3;p13), which seem to be recurrent and could influence clinical outcome. Also the present case confirms the impact of the translocation t(1;19) on central nervous system relapse, which should be studied for underlying mechanisms in future.
authors.affiliation: Molecular Biology and Biotechnology Department, Human Genetics Div., Atomic Energy Commission of Syria, P.O. Box 6091, Damascus, Syria.
authors.forename: Abdulsamad
authors.initials: A
authors.lastname: Wafa
authors.affiliation: Molecular Biology and Biotechnology Department, Human Genetics Div., Atomic Energy Commission of Syria, P.O. Box 6091, Damascus, Syria.
authors.forename: Manar
authors.initials: M
authors.lastname: As'sad
authors.affiliation: Jena University Hospital, Institute of Human Genetics, Kollegiengasse 10, D-07743, Jena, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Liehr
authors.affiliation: Molecular Biology and Biotechnology Department, Mammalians Biology Div., Flow-cytometry Lab., Atomic Energy Commission of Syria, P.O. Box 6091, Damascus, Syria.
authors.forename: Abdulmunim
authors.initials: A
authors.lastname: Aljapawe
authors.affiliation: Molecular Biology and Biotechnology Department, Human Genetics Div., Atomic Energy Commission of Syria, P.O. Box 6091, Damascus, Syria. ascientific@aec.org.sy.
authors.forename: Walid
authors.initials: W
authors.lastname: Al Achkar
mesh_terms: D000293:Adolescent; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage*; D002869:Chromosome Aberrations; D002878:Chromosomes, Human, Pair 1; D002882:Chromosomes, Human, Pair 13; D002885:Chromosomes, Human, Pair 16; D004317:Doxorubicin / Q000008:administration & dosage*; D017809:Fatal Outcome; D006297:Health Services Accessibility; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage*; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000235:genetics* / Q000276:immunology; D013593:Syria; D014178:Translocation, Genetic; D014750:Vincristine / Q000008:administration & dosage*
chemical_list: D000964:Antimetabolites, Antineoplastic; D015514:Oncogene Proteins, Fusion; C543638:TCF3-PBX1 fusion protein, human; D014750:Vincristine; D004317:Doxorubicin; D008727:Methotrexate
keywords: Acute lymphoblastic leukemia (ALL); Cytogenetics; Fluorescence in situ hybridization (FISH); Prognostic factors; TCF3-PBX1; t(1;19)