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Case Reports in Genetics
Volume 2012, Article ID 186532, 4 pages
http://dx.doi.org/10.1155/2012/186532
Case Report

Extra Copies of der(21)t(12;21) plus Deletion of ETV6 Gene due to dic(12;18) in B-Cell Precursor ALL with Poor Outcome

1Pediatric Oncohematology Center, Hospital Oswaldo Cruz, University of Pernambuco (CEONHPE/HUOC/UPE), 50050-210 Recife, PE, Brazil
2Institute of Biological Science, University of Pernambuco, 50050-210 Recife, PE, Brazil
3Departament of Genetics, Federal University of Pernambuco, 50670-901 Recife, PE, Brazil
4Institute of Human Genetics and Anthropology, 07740 Jena, Germany
5Department of Cytogenetics of the National Center for Bone Marrow Transplant (CEMO-INCA), National Cancer Institute, 20230-130 Rio de Janeiro, RJ, Brazil

Received 9 December 2011; Accepted 18 January 2012

Academic Editors: C. López Ginés, P. Saccucci, and G. Velagaleti

Copyright © 2012 Marina Araújo Fonzar Hernandes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Acute lymphoblastic leukemia (ALL), CD10+ B-cell precursor, represents the most frequent type of childhood ALL from 3 to 6 years of age. The t(12;21)(p13;q22) occurs in 25% of cases of B-cell precursor ALL, it is rare in children less than 24 months and have been related to good prognosis. Some relapse cases and unfavorable prognosis in ALL CD10+ are associated with t(12;21) bearing additional aberrations as extra copies of chromosome 21 and ETV6 gene loss. This report describes the case of a 15 month-year old girl, who displayed a karyotype with addition on chromosome 12p plus trisomy 10 and tetrasomy of chromosome 21. Molecular cytogenetic studies revealed two extra copies of the der(21) t(12;21), trisomy 10 and deletion of the second ETV6 gene due to the dic(12;18). These findings show the great importance of molecular cytogenetic studies to clarify complex karyotypes, to define prognostic, to carry out risk group stratification and to support correctly disease treatment in childhood acute lymphoblastic leukemia.