title: Prevalence of TEL/AML1 fusion gene in Brazilian pediatric patients with acute lymphoblastic leukemia.
abstract: We studied 58 childhood B-lineage acute lymphoblastic leukemia (B-ALL) in Brazilian sample patients at the time of diagnosis to investigate the prevalence of the cryptic t(12;21)(p13;q22). All bone marrow specimens were G-band karyotyped, and commercial dual-color DNA probes were used to search for fusion signals in nuclei. The karyotype analysis showed hyperdiploidy as the most frequent abnormality. The frequency of patients with TEL/AML1 gene fusion was 19% (11 out of 58 cases). Six of the positive samples had normal karyotypes. Deletion of the wild-type TEL allele was observed in 27.3% of TEL/AML1 fusion-positive cases, but it was also identified in 4.2% of the negative cases. Three cases presented two fusion signals, indicating possible duplication of the der(21). The mean age of the patients with TEL/AML1 fusion was 4.8 years and the mean amount of peripheral leukocytes was 44,270 x 10(6)/L. The higher frequency of females with B-ALL (33/58 cases) observed in our sample was probably due to the selection mode of the study cases. The prevalence of TEL/AML1 fusion in Brazilian children in our study is similar to that found in other populations.
authors.affiliation: Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves 9500, Porto Alegre 91540-000, RS, Brazil.
authors.forename: P R G
authors.initials: PR
authors.lastname: Zen
authors.forename: M C
authors.initials: MC
authors.lastname: Lima
authors.forename: V M
authors.initials: VM
authors.lastname: Coser
authors.forename: L
authors.initials: L
authors.lastname: Silla
authors.forename: L
authors.initials: L
authors.lastname: Daudt
authors.forename: M S
authors.initials: MS
authors.lastname: Fernandes
authors.forename: J
authors.initials: J
authors.lastname: Neumann
authors.forename: M S
authors.initials: MS
authors.lastname: Mattevi
authors.forename: R
authors.initials: R
authors.lastname: Ortigara
authors.forename: G A
authors.initials: GA
authors.lastname: Paskulin
mesh_terms: D001938:Brazil; D002051:Burkitt Lymphoma / Q000235:genetics*; D002648:Child; D002881:Chromosomes, Human, Pair 12; D002891:Chromosomes, Human, Pair 21; D050676:Core Binding Factor Alpha 2 Subunit; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D015335:Molecular Probes; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D011003:Ploidies; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D014178:Translocation, Genetic; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D015335:Molecular Probes; D015514:Oncogene Proteins, Fusion; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein