RESUMEN
BACKGROUND: The Italian external quality assessment scheme in classical cytogenetics was started in 2001 as an activity funded by the National Health System and coordinated by the Italian Public Institute of Health. OBJECTIVES: The aim of our work is to present data from the first 4 years of activity, 2001-2004. METHODS: Italian cytogenetics public laboratories were enrolled on a voluntary basis, and this nationwide program covered prenatal, postnatal and oncological diagnosis. The scheme is annual and retrospective; a panel of experts reviewed the quality of images and reports in order to assess technical, analytical and interpretative performance. RESULTS: Over the 4-year period, the number of participating laboratories increased: from 36 in 2001, 46 in 2002, 49 in 2003 to 51 in 2004. The overall technical performance was satisfactory. Inadequacy or lack of information in reporting was the most frequent analytical inaccuracy identified in all parts of the scheme. However, the percentage of complete reports increased significantly during the period: by 36% in postnatal diagnosis between 2001 and 2004 (p < 0.001) and by 42% in oncological diagnosis between 2002 and 2004 (p = 0.003). CONCLUSIONS: Our experience reveals that participation in external quality assessment programs has significant advantages, helping to standardize and to assure quality in cytogenetic testing.
Asunto(s)
Análisis Citogenético/métodos , Análisis Citogenético/normas , Pruebas Genéticas , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Neoplasias/diagnóstico , Garantía de la Calidad de Atención de Salud , Genotipo , Humanos , Italia , Neoplasias/genética , Diagnóstico Prenatal , Factores de TiempoRESUMEN
Fluorescence in situ hybridization and comparative genomic hybridization characterized 6p rearrangements in eight primary and in 10 secondary myeloid disorders (including one patient with Fanconi anemia) and found different molecular lesions in each group. In primary disorders, 6p abnormalities, isolated in six patients, were highly heterogeneous with different breakpoints along the 6p arm. Reciprocal translocations were found in seven. In the 10 patients with secondary acute myeloid leukemia/myelodysplastic syndrome (AML/MDS), the short arm of chromosome 6 was involved in unbalanced translocations in 7. The other three patients showed full or partial trisomy of the 6p arm, that is, i(6)(p10) (one patient) and dup(6)(p) (two patients). In 5/7 patients with unbalanced translocations, DNA sequences were overrepresented at band 6p21 as either cryptic duplications (three patients) or cryptic low-copy gains (two patients). In the eight patients with cytogenetic or cryptic 6p gains, we identified a common overrepresented region extending for 5-6 megabases from the TNF gene to the ETV-7 gene. 6p abnormalities were isolated karyotype changes in four patients. Consequently, in secondary AML/MDS, we hypothesize that 6p gains are major pathogenetic events arising from acquired and/or congenital genomic instability.
Asunto(s)
Cromosomas Humanos Par 6/genética , Leucemia Mieloide/genética , Síndromes Mielodisplásicos/genética , Neoplasias Primarias Secundarias/genética , Translocación Genética/genética , Enfermedad Aguda , Adulto , Anciano , Anciano de 80 o más Años , Análisis Citogenético , Femenino , Humanos , Hibridación Fluorescente in Situ , Leucemia Mieloide/diagnóstico , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/diagnóstico , Neoplasias Primarias Secundarias/diagnóstico , Sensibilidad y EspecificidadRESUMEN
To better define the incidence and significance of cryptic chromosome lesions in acute myeloid leukemia (AML), fluorescence in situ hybridization (FISH) studies were performed in interphase cells and, when appropriate, in metaphase cells and in morphologically intact BM smears. Fifty-five adult de novo AML (group A) and 27 elderly AML or AML after myelodysplastic syndrome (AML-MDS) (group B) were tested using probes detecting the following anomalies: -5, -7, +8, deletions of 5q31, 7q31, 12p13/ETV6, 17p13/p53, 20q11. All the patients had a normal karyotype in more than 20 cells and tested negative for the common AML-associated fusion genes. No patient in group A was found to carry occult chromosome anomalies, whereas 8/27 patients in group B (P < 0.0001) showed 5q31 or 7q31 deletion (three cases each), a 17p13/p53deletion or trisomy 8 (one case each) in 33-60% interphase cells. Metaphase cells showed only one hybridization signal at 5q31 (three cases) and 7q31 (one case), whereas two normal signals at 7q31 and chromosome 8 centromeres were seen in two patients with 7q deletion and trisomy 8 in interphase cells. The majority of blast cells (76-94%) carried the chromosome anomaly in all cases; erythroid involvement in a minority of cells was seen in three patients. In group B, the presence of occult chromosome anomalies was associated with exposure to myelotoxic agents in the workplace (5/8 cases vs 3/19, P = 0.026) and with a lower complete remission rate (0/6 patients vs 7/12, P = 0.024). We arrived at the following conclusions: (1) cryptic chromosome deletions in the order of a few hundred kb magnitude may be found in a fraction of elderly AML or MDS-related AML and not in de novo adult AML with normal karyotype; (2) these chromosome lesions are usually represented by submicroscopic rearrangements; (3) they display a specific pattern of cell-lineage involvement arguing in favor of their role in the outgrowth of the leukemic blast cells; (4) they are associated with a history of exposure to myelotoxic agents in the workplace and, possibly, with resistance to induction treatment.
Asunto(s)
Linaje de la Célula/genética , Aberraciones Cromosómicas , Cromosomas Humanos Par 7/genética , Leucemia Mieloide/genética , Síndromes Mielodisplásicos/genética , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Médula Ósea/patología , Humanos , Hibridación Fluorescente in Situ , Cariotipificación , Leucemia Mieloide/patología , Persona de Mediana Edad , Síndromes Mielodisplásicos/patología , Trisomía/diagnósticoRESUMEN
In a case of acute monocytic leukemia, M5a according to the FAB classification, with a 48,XY,+8,+22 karyotype, amplification of the CBFbeta/MYH11 fusion transcript type A was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Fluorescence in situ hybridization (FISH) using an appropriate panel of DNA probes showed that insertion of the 3'-MYH11 within the CBFbeta gene on chromosome 16q22 was the mechanism producing the same molecular rearrangement as in typical inv(16)(p13q22)/t(16;16)(p13;q22).
Asunto(s)
Cromosomas Humanos Par 16/genética , Cromosomas Humanos Par 22/genética , Cromosomas Humanos Par 8/genética , Leucemia Monocítica Aguda/genética , Proteínas de Fusión Oncogénica/genética , Trisomía , Adulto , Humanos , Hibridación Fluorescente in Situ , Leucemia Monocítica Aguda/patología , MasculinoRESUMEN
Two patients with "de novo" ANLL and tetrasomy of chromosome 8 at diagnosis are described. A mosaic karyotype with coexistence of normal metaphases was found in both cases. Trisomy 8 was also present in one metaphase of the first patient. Fluorescent in situ hybridization with a centromeric probe from chromosome 8 was applied in the second case, confirming the presence of a minor population with trisomy 8 in interphase nuclei.
Asunto(s)
Aneuploidia , Cromosomas Humanos Par 8 , Leucemia Mieloide Aguda/genética , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Hibridación Fluorescente in Situ , Cariotipificación , MasculinoRESUMEN
Thirty-six sex-mismatched transplants were studied using fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) methods. Molecular cytogenetics was performed using interphase FISH with a centromeric probe for chromosome Y, and PCR amplification was performed with a set of VNTR microsatellite loci. In addition, reverse transcriptase-PCR (RT-PCR) for BCR-ABL fusion was used to investigate cases of Philadelphia chromosome (Ph)-positive chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL). Our integrated approach of post-transplant monitoring was helpful in documenting successful transplants and in controlling the size of Ph-positive clones in CML. A striking overlap was found between results from FISH analysis and PCR for polymorphic loci.
Asunto(s)
Trasplante de Médula Ósea , Proteínas de Fusión bcr-abl/genética , Trasplante de Células Madre Hematopoyéticas , Hibridación Fluorescente in Situ , Repeticiones de Minisatélite , Cromosoma Y , Adolescente , Adulto , Niño , Femenino , Antígenos HLA , Histocompatibilidad , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/terapia , Masculino , Persona de Mediana Edad , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
We describe two cases of acute myelocytic leukemia (AML), classified as M4 and M1 in the French-American-British classification, with unbalanced translocations der(16)t(11;16)(q23;p13) and der(18)t(11;18) (q22;p11.2), respectively. Molecular studies using Southern blot and reverse transcriptase-polymerase chain reaction showed an MLL rearrangement due to an internal duplication of the gene in both cases. Fluorescence in situ hybridization disclosed the presence of an extra copy of the MLL gene on 16p13 and 18p11.2, respectively, as a result of the partial trisomy of chromosome 11q. Our two cases clearly show that tandem duplication of the MLL gene may occur in AML with a partial 11q trisomy. Thus, systematic screening of this molecular defect should be performed in patients with unbalanced translocations involving 11q22 approximately q23-->qter.
Asunto(s)
Cromosomas Humanos , Proteínas de Unión al ADN/genética , Duplicación de Gen , Leucemia Mieloide Aguda/genética , Proto-Oncogenes , Factores de Transcripción , Translocación Genética , Adulto , Southern Blotting , Análisis Citogenético , Femenino , N-Metiltransferasa de Histona-Lisina , Humanos , Hibridación Fluorescente in Situ , Leucemia Mieloide Aguda/etiología , Leucemia Mieloide Aguda/terapia , Masculino , Persona de Mediana Edad , Proteína de la Leucemia Mieloide-Linfoide , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Clonal hematopoiesis with trisomy 6 as the sole karyotypic change was revealed by cytogenetics in two cases of aplastic anemia. In both patients, dyserythropoiesis was characterized by asynchrony of maturation between nucleus and cytoplasm, binucleated elements, and intercytoplasmic connections. In addition to conventional cytogenetics, the size of the trisomic clone was evaluated by fluorescence in situ hybridization on fixed cells at diagnosis and in the course of the disease by using an alpha-satellite centromeric probe for chromosome 6. Moreover, in situ hybridization on bone marrow smears showed that dysplastic erythrocytes as well as myeloid cells belonged to the trisomic clone. Trisomy 6 identifies a subgroup of hematologic disorders with bone marrow hypo-aplasia and dyserythropoiesis.
Asunto(s)
Anemia Aplásica/genética , Células de la Médula Ósea/patología , Cromosomas Humanos Par 6/genética , Trisomía/genética , Anemia Aplásica/patología , Células Clonales/patología , Femenino , Humanos , Hibridación Fluorescente in Situ , Cariotipificación , Persona de Mediana Edad , Trisomía/patologíaRESUMEN
The ALL1 gene at 11q23 is a promiscuous gene participating in chromosomal abnormalities of acute leukemias with 1 of over 30 potential partner genes. Among these, the AF10 gene at band 10p12 has been recently cloned and characterized. Acute leukemias with the ALL1/AF10 chimeric gene frequently show heterogeneity in the breakpoints on 10p, as well as complex insertion (10;11) as a result of complex molecular mechanisms leading to the ALL1/AF10 fusion. In this context, we report the first description of an infant acute lymphoblastic leukemia with an interstitial insertion of the AF10 gene into the 11q23 band, resulting in the transcription of the ALL1/AF10 fusion product. Furthermore, we show how different diagnostic tools such as molecular, cytogenetic, and fluorescence in situ hybridization (FISH) analyses should be combined to resolve complex situations in the 11q23 setting.
Asunto(s)
Cromosomas Humanos Par 10/genética , Cromosomas Humanos Par 12/genética , Proteínas de Unión al ADN/genética , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proto-Oncogenes , Factores de Transcripción/genética , Translocación Genética/genética , Proteínas de Unión al ADN/análisis , Femenino , N-Metiltransferasa de Histona-Lisina , Humanos , Hibridación Fluorescente in Situ , Recién Nacido , Proteína de la Leucemia Mieloide-Linfoide , Proteínas de Fusión Oncogénica/análisis , Factores de Transcripción/análisisRESUMEN
We describe two cases of acute myeloblastic leukemia, classified as M4 and M5 in the French-American-British nomenclature, with an 11q23 rearrangement at karyotypic analysis. The involvement of the MLL gene with two new partner loci on chromosome 10q22 and 8q24, respectively, was demonstrated by fluorescence in situ hybridization using a YAC clone B22B2L.
Asunto(s)
Cromosomas Humanos Par 10 , Cromosomas Humanos Par 11 , Cromosomas Humanos Par 8 , Proteínas de Unión al ADN/genética , Leucemia Monocítica Aguda/genética , Leucemia Mielomonocítica Aguda/genética , Proto-Oncogenes , Factores de Transcripción , Translocación Genética , Adulto , Crisis Blástica , Médula Ósea/patología , Bandeo Cromosómico , Mapeo Cromosómico , Femenino , N-Metiltransferasa de Histona-Lisina , Humanos , Inmunofenotipificación , Hibridación Fluorescente in Situ , Cariotipificación , Leucemia Monocítica Aguda/sangre , Leucemia Monocítica Aguda/inmunología , Leucemia Monocítica Aguda/patología , Leucemia Mielomonocítica Aguda/sangre , Leucemia Mielomonocítica Aguda/patología , Masculino , Persona de Mediana Edad , Proteína de la Leucemia Mieloide-Linfoide , Dedos de ZincAsunto(s)
Cromosomas Humanos Par 16 , Cromosomas Humanos Par 5 , Fusión Génica , Leucemia Mielomonocítica Crónica/genética , Síndrome de Noonan/genética , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/genética , Metiltransferasa de ADN de Sitio Específico (Adenina Especifica)/genética , Transcripción Genética , Adulto , Secuencia de Bases , Femenino , Humanos , Hibridación Fluorescente in Situ , Translocación GenéticaAsunto(s)
Fusión Génica , Síndrome Hipereosinofílico/genética , ARN Mensajero/genética , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/genética , Tropomiosina/genética , Cromosomas Humanos Par 1 , Cromosomas Humanos Par 10 , Cromosomas Humanos Par 5 , Enfermedad Crónica , Cartilla de ADN , Humanos , Síndrome Hipereosinofílico/patología , Hibridación Fluorescente in Situ , Datos de Secuencia Molecular , Neoplasias de la Tiroides/genéticaAsunto(s)
Cromosomas Humanos Par 3/genética , Cromosomas Humanos Par 5/genética , Regulación Leucémica de la Expresión Génica , Leucemia Mieloide/tratamiento farmacológico , Leucemia Mieloide/genética , Proteínas Nucleares/genética , Proteínas de Fusión Oncogénica/genética , Enfermedad Aguda , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Humanos , Proteínas Nucleares/biosíntesis , Nucleofosmina , Proteínas de Fusión Oncogénica/análisis , Proteínas de Fusión Oncogénica/biosíntesis , Fracciones Subcelulares/química , Translocación Genética/genéticaRESUMEN
The t(10;11)(p12;q14) is a recurring chromosomal translocation that gives rise to the CALM/AF10 fusion gene, which is found in acute myeloid leukemia, acute lymphoblastic leukemia and malignant lymphoma. We analyzed the fusion transcripts in 20 new cases of CALM/AF10-positive leukemias, and compared the gene expression profile of 10 of these to 125 patients with other types of leukemia and 10 normal bone marrow samples. Based on gene set enrichment analyses, the CALM/AF10-positive samples showed significant upregulation of genes involved in chromatin assembly and maintenance and DNA repair process, and downregulation of angiogenesis and cell communication genes. Interestingly, we observed a striking upregulation of four genes located immediately centromeric to the break point of the t(10;11)(p12;q14) on 10p12 (COMMD3 (COMM domain containing 3), BMI1 (B lymphoma Mo-MLV insertion region 1 homolog), DNAJC1 (DnaJ (Hsp40) homolog subfamily C member 1) and SPAG6 (sperm associated antigen 6)). We also conducted semiquantitative reverse transcriptase-PCR analysis on leukemic blasts from a murine CALM/AF10 transplantation model that does not have the translocation. Commd3, Bmi1 and Dnajc1, but not Spag6 were upregulated in these samples. These results strongly indicate that the differential regulation of these three genes is not due to the break point effect but as a consequence of the CALM/AF10 fusion gene expression, though the mechanism of regulation is not well understood.
Asunto(s)
Ensamble y Desensamble de Cromatina/genética , Sitios Frágiles del Cromosoma , Cromosomas Humanos Par 10 , Reparación del ADN/genética , Leucemia/genética , Proteínas de Ensamble de Clatrina Monoméricas/genética , Factores de Transcripción/genética , Regulación hacia Arriba , Animales , Humanos , Ratones , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Translocación GenéticaAsunto(s)
Orden Génico , Hibridación Fluorescente in Situ/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Transactivadores/genética , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , MasculinoAsunto(s)
Transformación Celular Neoplásica/patología , Leucemia Linfocítica Crónica de Células B/patología , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Neoplasias Primarias Secundarias/etiología , Linaje de la Célula/genética , Linaje de la Célula/inmunología , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/inmunología , Células Clonales/patología , Análisis Citogenético , Humanos , Inmunofenotipificación , Leucemia Linfocítica Crónica de Células B/etiología , Leucemia Mielógena Crónica BCR-ABL Positiva/etiología , Linfocitos/patología , Persona de Mediana Edad , Células Mieloides/patología , Neoplasias Primarias Secundarias/patologíaRESUMEN
This review focuses on karyotypic and molecular findings of myelodysplastic syndromes (MDS). Genetic entities are distinct on the basis of structural (deletions, translocations, inversions) or numerical chromosomal abnormalities (trisomies, monosomies). New information about the amount and nature of malignant cells in MDS, as well as of genes rearranging in specific translocations, recently provided by molecular cytogenetics, are analysed. Integration of clinical-haematological classifications with cytogenetic and molecular findings is discussed
Asunto(s)
Aberraciones Cromosómicas , Trastornos de los Cromosomas , Cromosomas Humanos , Síndromes Mielodisplásicos/genética , Adulto , Niño , Deleción Cromosómica , Femenino , Humanos , Cariotipificación , Masculino , Translocación GenéticaRESUMEN
Diabetes insipidus and thrombocytosis were presenting symptoms in a case of adult ANLL-M1. Cytogenetic investigations revealed a typical 3q rearrangement, i.e. inv(3)(q21q26). A subclone with monosomy 7 was also found and documented by FISH analysis. Correlations between clinical/hematological features and cytogenetic/FISH results are discussed.