RESUMO
A translocation (6;11)(q26-27;q23) was detected in four male patients diagnosed with acute T-cell lymphoblastic leukemia and acute myelomonocytic and monocytic leukemias. This acquired reciprocal translocation appears to be associated with acute leukemias in young men who present clinically with localized infection, and a moderate leukocytosis. There was a poor response to antileukemic chemotherapy and a short overall survival. Aggressive treatment strategies should be considered in the treatment of these high-risk leukemias.
Assuntos
Cromossomos Humanos Par 11 , Cromossomos Humanos Par 6 , Leucemia Monocítica Aguda/genética , Leucemia Mielomonocítica Aguda/genética , Leucemia-Linfoma de Células T do Adulto/genética , Translocação Genética/genética , Adolescente , Adulto , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , PrognósticoRESUMO
Two cases of Philadelphia chromosome positive chronic myelogenous leukemia (CML) demonstrated ring chromosomes. The appearance of the ring coincided with evolution from the stable to the aggressive phase. A literature search yielded six other cases of ring chromosomes in CML; all were in or were entering the aggressive phase of the disease. Thus, as is the case with acute nonlymphocytic leukemia, in CML the finding of an acquired ring chromosome is associated with a poor prognosis.
Assuntos
Aberrações Cromossômicas , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mieloide/genética , Cromossomos em Anel , Adulto , Transformação Celular Neoplásica , Feminino , Humanos , Cariotipagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Mieloide/patologia , Leucemia Mieloide de Fase Acelerada/genética , Leucemia Mieloide de Fase Acelerada/patologia , PrognósticoRESUMO
We describe a cytogenetic abnormality with important diagnostic and prognostic implications. The translocation t(1;3)(p36;q21) is an acquired chromosomal rearrangement associated with myelodysplastic syndromes, which have a high propensity for conversion to refractory acute nonlymphocytic leukemia.
Assuntos
Cromossomos Humanos Par 1 , Cromossomos Humanos Par 3 , Síndromes Mielodisplásicas/genética , Translocação Genética , Adolescente , Adulto , Bandeamento Cromossômico , Feminino , Marcadores Genéticos , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/diagnóstico , Pré-Leucemia/genética , PrognósticoRESUMO
Assessment of cytogenetic patterns associated with chronic myelogenous leukemia (CML) suggests that genetic events at band q34 of chromosome nine are critical in the conversion of benign to malignant hematopoiesis. A break at this band is identified in almost all cases of Philadelphia chromosome (Ph1) positive CML, is also noted in some cases of Ph1 negative CML and cannot be excluded in the remaining cases. The human cellular homolog of the Abelson retrovirus oncogene (c-abl) is situated at band 9q34 and is translocated with the genetic sequences distal to the break point at this site in Ph1 positive disease. This oncogene has been shown experimentally to transform pre-B cells and it is expressed in primitive cells of the granulocytic series which are involved in CML. Although the break in CML chromosomes at 9q34 and the location of c-abl at 9q34 could be unrelated, it seems more likely that the two genetic events are associated with evolution of malignant hematopoiesis of man.
Assuntos
Cromossomos Humanos 6-12 e X , Leucemia Mieloide/genética , Vírus da Leucemia Murina de Abelson/genética , Aberrações Cromossômicas/genética , Transtornos Cromossômicos , Cromossomos Humanos 21-22 e Y , Humanos , Cariotipagem , Translocação GenéticaRESUMO
Approximately 78% of chronic myelogenous leukemia patients have the standard Ph' chromosome-negative defect as their only chromosomal abnormality. CML has been extensively studied due to the availability of tumor tissue and the frequency and consistency with which such abnormalities are noted. There have been few cases reported, however, of Ph' chromosome-negative CML with an abnormality involving rearrangement and breaks at the 9q34 band. We report here a unique case of the fourth Ph'-negative patient who demonstrates this break.
Assuntos
Cromossomos Humanos 21-22 e Y , Cromossomos Humanos 6-12 e X , Leucemia Mieloide/genética , Translocação Genética , Pré-Escolar , Bandeamento Cromossômico , Feminino , Humanos , CariotipagemRESUMO
To determine if abnormalities exist in the bone marrow stroma in Fanconi's anaemia, we studied the cytogenetic composition of in vitro bone marrow fibroblastic cells (FC) from a patient with this disorder and compared it to those obtained from skin fibroblasts, peripheral blood lymphocytes, and direct bone marrow preparations. The presence of granulocytic progenitors in bone marrow and T lymphocyte colonies in peripheral blood was also determined in addition to the ability of this patient's FC to stimulate normal granulocytic progenitors. We found that the FC had far fewer chromosomal abnormalities and stimulated normally the growth of granulocyte colonies. Granulocyte progenitors were not found, but T lymphocyte colonies were abundant. These results support the concept that a defect in haematopoietic stromal elements is not responsible for the aplasia developing in the disorder.
Assuntos
Anemia Aplástica/patologia , Medula Óssea/ultraestrutura , Anemia de Fanconi/patologia , Granulócitos/fisiologia , Hematopoese , Adolescente , Células Cultivadas , Bandeamento Cromossômico , Ensaio de Unidades Formadoras de Colônias , Anemia de Fanconi/genética , Fibroblastos/ultraestrutura , Humanos , Linfócitos/ultraestrutura , Masculino , Pele/ultraestruturaRESUMO
The cytogenetic status of bone marrow stromal elements obtained from six patients with Ph1-positive chronic myelogenous leukemia (CML), two in blast crisis, was studied in vitro utilizing the potential of marrow to form surface-adherent colonies morphologically compatible with mesenchymal elements. We demonstrated the absence of both the marker chromosome and other chromosomal abnormalities in all the fibroblastic colonies studied, indicating that the progenitors of such colonies (plaque-forming units in culture, PFU-C) are not closely related to hematopoietic elements including macrophages. This supports previous reports suggesting that the stromal elements in myelofibrosis associated with CML are not derived from the primary Ph1-positive malignant clone but represent a stromal reactive component of benign or independent malignant potential.
