RESUMO
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.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Cromossomos Humanos Par 13 , Cromossomos Humanos Par 8 , Leucemia Mieloide Aguda/induzido quimicamente , Leucemia Mieloide Aguda/genética , Translocação Genética , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Ósseas/cirurgia , Aberrações Cromossômicas , Cromossomos Humanos Par 13/genética , Cromossomos Humanos Par 8/genética , Análise Citogenética , Humanos , Cariotipagem/métodos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/cirurgia , Masculino , Segunda Neoplasia Primária/induzido quimicamente , Segunda Neoplasia Primária/genética , Osteossarcoma/tratamento farmacológico , Osteossarcoma/genética , Osteossarcoma/patologia , Osteossarcoma/cirurgiaRESUMO
Acute myeloid leukemia in childhood is a heterogeneous group of diseases, and different epidemiologic factors are involved in the etiopathogenesis. Genetic syndromes are one of the predisposing factors of acute myeloid leukemia (AML), including Down syndrome, Bloom syndrome, and neurofibromatosis. Acute megakaryoblastic leukemia (AMKL) is the main subtype in Down syndrome infants, and acquired chromosomal anomalies are closely related to the physiopathology of the illness. The main chromosomal anomalies in AMKL are structural, such as t(1;22); however, complex karyotypes are also common. Here we describe the case of an infant with neurofibromatosis developing AMKL with a complex karyotype including 5q and 17q deletions, TP53 deletion, and an unusual unbalanced chromosomal translocation t(11;19)(q13;p13), leading to three copies of the MLL gene.
Assuntos
Hibridização in Situ Fluorescente/métodos , Leucemia Megacarioblástica Aguda/genética , Neurofibromatoses/genética , Feminino , Genes p53 , Histona-Lisina N-Metiltransferase , Humanos , Lactente , Cariotipagem , Proteína de Leucina Linfoide-Mieloide/genéticaAssuntos
Cromossomos Humanos Par 13/genética , Cromossomos Humanos Par 3/genética , Células Matadoras Naturais/patologia , Leucemia Mieloide Aguda/patologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Translocação Genética/genética , Adolescente , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Masculino , Fenótipo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , PrognósticoRESUMO
Hyperdiploidy is rarely observed in childhood acute myeloid leukemia (AML). Described here is the case of a 2(1/2)-year-old girl with AML-M5 and 51 chromosomes characterized by double tetrasomy of chromosomes 8 and 21 and also a neocentric derivative chromosome neo(1)(qter-->q23 approximately 24::q23 approximately 24-->q43-->neo-->q43-->qter). Little is known about the prognostic significance of these chromosomal abnormalities in childhood AML. In the actual case, complete remission was achieved after chemotherapy, which continued for 7 months. No acquired neocentric chromosome 1 has been described previously, even though neocentromere formation has been reported for other chromosomes in neoplasms.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 21 , Cromossomos Humanos Par 8 , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Pré-Escolar , Feminino , Humanos , Hibridização in Situ Fluorescente , CariotipagemRESUMO
We report the case of a five-month-old black male infant who had recurrent episodes of respiratory infections and also presented anemia and enlargements of the spleen, liver and lymphnodes. Hematological analysis revealed morphological abnormalities with megaloblastic dyserythropoiesis, while fetal hemoglobin assaying showed normal levels. Conventional and molecular cytogenetic analysis revealed monosomy of chromosome 7. Despite all therapeutic efforts during allogenic bone marrow transplantation, the child died due to generalized infection. The clinical and genetic distinctions between monosomy 7 syndrome and myelodysplastic disorders in childhood are discussed.