title: Cytogenetic and Molecular Findings in Children with Acute Lymphoblastic Leukemia: Experience of a Single Institution in Argentina.
abstract: The purpose of the current study was to evaluate the cytogenetic findings in 1,057 children with acute lymphoblastic leukemia (ALL) referred to the cytogenetics laboratory at the Hospital de Pediatría Dr. Juan P. Garrahan, between 1991 and 2014. Chromosomal abnormalities were evaluated by G-banding and FISH. Since December 2002, RT-PCR determinations were systematically carried out for BCR-ABL1, KMT2A-AFF1, ETV6-RUNX1, and TCF3-PBX1 rearrangements in children, adding KMT2A-MLLT3 and KMT2A-MLLT1 in infants. The percentage of abnormalities detected by cytogenetics was 70.1%. Four novel abnormalities, t(2;8)(p11.2;p22), inv(4)(p16q25), t(1;7)(q25;q32), and t(5;6)(q21;q21), were found in this cohort. We compared cytogenetic and RT-PCR results for BCR-ABL1, KMT2A-AFF1 and TCF3-PBX1 rearrangements in 497 children evaluated by both methods. The results were highly concordant (p < 0.7), and interestingly, FISH was relevant to confirm G-banding findings that were discordant with RT-PCR studies. This study showed the importance of performing G-banding, FISH and RT-PCR simultaneously to improve the detection of chromosomal abnormalities considering their important value in the diagnosis and prognosis of childhood ALL patients. Finally, to the best of our knowledge, this is the first series of cytogenetic findings in children with ALL reported in Argentina.
authors.affiliation: Cytogenetics Laboratory, Genetics Department, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Mariela C
authors.initials: MC
authors.lastname: Coccé
authors.affiliation: Department of Hematology and Oncology, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Cristina N
authors.initials: CN
authors.lastname: Alonso
authors.affiliation: Department of Immunology and Rheumatology, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Rossi
authors.affiliation: Department of Immunology and Rheumatology, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Andrea R
authors.initials: AR
authors.lastname: Bernasconi
authors.affiliation: Cytogenetics Laboratory, Genetics Department, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Rampazzi
authors.affiliation: Department of Hematology and Oncology, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Maria S
authors.initials: MS
authors.lastname: Felice
authors.affiliation: Department of Hematology and Oncology, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Rubio
authors.affiliation: Department of Hematology and Oncology, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Silvia
authors.initials: S
authors.lastname: Eandi Eberle
authors.affiliation: Department of Hematology and Oncology, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Adriana
authors.initials: A
authors.lastname: Medina
authors.affiliation: Cytogenetics Laboratory, Genetics Department, Hospital de Pediatría 'Prof Dr. Juan P. Garrahan', Buenos Aires, Argentina.
authors.forename: Marta S
authors.initials: MS
authors.lastname: Gallego
keywords: Childhood acute lymphoblastic leukemia; Chromosomal abnormalities; FISH; RT-PCR