In about 50% of first trimester spontaneous abortion the cause remains undetermined after standard cytogenetic investigation. We evaluated the usefulness of array-CGH in diagnosing chromosome abnormalities in products of conception from first trimester spontaneous abortions. Cell culture was carried out in short-and long-term cultures of 54 specimens and cytogenetic analysis was successful in 49 of them. Cytogenetic abnormalities (numerical and structural) were detected in 22 (44.89%) specimens. Subsequent, array-CGH based on large insert clones spaced at 1 Mb intervals over the whole genome was used in 17 cases with normal G-banding karyotype. This revealed chromosome aneuplodies in three additional cases, giving a final total of 51% cases in which an abnormal karyotype was detected. In keeping with other recently published works, this study shows that array-CGH detects abnormalities in a further~10% of spontaneous abortion specimens considered to be normal using standard cytogenetic methods. As such, array-CGH technique may present a suitable complementary test to cytogenetic analysis in cases with a normal karyotype.
We report on a 15-year-old girl with mental retardation, obesity, short stature and minor anomalies. She had 47 chromosomes with a minute extra ring which was identified by FISH to be derived from chromosome 17.
A leucemia promielocítica aguda (LPA) corresponde a 10% -15% das leucemias mielóides agudas (LMA). Este tipo de leucemia (LMA-M3
Palavras-chave: Leucemia promielocítica aguda; análise citogenética; hibridação in situ fluorescente (FISH).
IntroduçãoA leucemia promielocítica aguda (LPA) ou LMA-M3, de acordo com a classificação FAB, corresponde a 10% -15% das leucemias mielóides agudas (LMA). Este tipo de leucemia apresenta morfologia celular característica com promielócitos anormais, núcleo excêntrico, abundantes granulações no citoplasma. Caracteriza-se também pela presença de múltiplos bastonetes de Auer no citoplasma, formando feixes, dando a estas células a denominação de "Faggot cells" (células com maços ou feixes). 1 Estudos de marcadores de superfície mostram que as células da LPA têm um padrão distinto quando comparado a outras LMAs. Ocorre alta expressão de antígenos mielomonocíticos (CD13, CD15 e CD33) e ausência de expressão de antígenos monocíticos (CD14, incluindo My4, Leu M3 e Mo2) e HLA-DR. 2,3,4 Em cerca de 90% dos casos, está associada à translocação t(15;17)(q22;q21), que resulta na
Bacal NS et al Rev. bras. hematol. hemoter. 2005;27(1):31-36 Artigo / Article Mieloma Múltiplo: 50 casos diagnosticados por citometria de fluxo Multiple Myeloma: 50 cases diagnosed by flow cytometry O Mieloma Mútiplo é uma doença de evolução heterogênea, na qual a maioria dos pacientes recai muito precocemente após o tratamento. Nesse contexto, o objetivo principal deste trabalho é relatar diferentes estratégias de análise do mieloma por citometria de fluxo e sua importância na associação com citogenética no diagnóstico de doença residual. Entre 2.450 casos de doenças onco-hematológicas estudados, de setembro de 1993 a agosto de 2004, foram diagnosticados 50 (2,0%) Mieloma Múltiplo. Foram feitas análises morfológicas e, até o ano de 2000, as imunofenotipagens foram realizadas no citômetro de fluxo XL-MCL (Coulter) pela estratégia tamanho/ complexidade, utilizando os anticorpos monoclonais CD19, CD20, CD38, CD45, CD56, HLA-DR, kappa e lambda de superfície e intracitoplasmáticas. A partir de 2001 passaram-se a utilizar painéis seqüenciais através do histograma CD138/ Complexidade e anticorpos monoclonais CD19, CD38, CD56, CD117, kappa e lambda intracitoplasmáticas. Mais recentemente foram incluídos no painel os anticorpos CD45, HLA-DR e CD33. A análise do DNA foi realizada por citometria com auxílio do programa Multicycle em nove amostras, sendo que sete apresentaram população aneuplóide. O cariótipo com banda G foi realizado em 25 casos, e a pesquisa de deleção do 13q por FISH em 15. Alterações cromossômicas foram encontradas em 4 casos, sendo duas deleções de 13q confirmadas por FISH. A mudança na estratégia de gates associada à citogenética e ao estudo da cinética do ciclo do DNA permitem melhor identificação de células plasmáticas anômalas, avaliação do prognóstico e detecção de doença residual. Rev. bras. hematol. hemoter. 2005;27(1):31-36. Palavras-chave: Mieloma Múltiplo; citometria de fluxo; citogenética; doença residual. Rev. bras. hematol. hemoter. 2005;27(1):31-36 Bacal NS et al kinetics of DNA are all data that permit better identification of anomalous plasma cells and therefore detection of minimal residual disease, that probably correlates with relapse prognosis. Rev. bras. hematol. hemoter. 2005;27(1):31-36.
The 8;21 translocation in acute myeloid leukemia (AML) results in a consistent fusion transcript, AML1/ETO. Long-term clinical remission occurs in some patients despite incomplete eradication of AML1/ETO as demonstrated by RT-PCR, thus limiting the usefulness of this assay. An important future goal will be to determine if there is a level of minimal residual disease (MRD) in patients below which relapse is unlikely. For the detection of MRD, we have developed reagents for fluorescence in situ hybridization (FISH) that identify both derivative 8 and 21 chromosomes with a high analytical sensitivity. In t(8;21) AML cells, two fused signals were detected in addition to the normal 8 and 21 alleles. The sensitivity and specificity of this probe mixture were analyzed in cell lines and patient bone marrows. One and two randomly juxtaposed signals were observed in 2.4 and 0.04% of normal cells, respectively. However, these were easily differentiated from t(8;21) cells by the absence of signals from the normal alleles. Using as criteria the presence of two fused signals plus the normal alleles, we observed no false positives among 5,000 normal cells. The probe correctly identified 20/20 patients with t(8;21) AML and 10/10 non-t(8;21) patients. In cell dilution experiments, the analytical sensitivity of this reagent was equal to that of the X chromosome and Y chromosome alpha-satellite probes. These optimized probes should facilitate the quantitative assessment and study of MRD in t(8;21) AML.
Between 1982 and 1985, 109 infants were referred for cytogenetic examination out of a population of 73,192 liveborn infants from eight maternity hospitals surveyed by the ECLAMC/MONITOR program. Thirty-one of the children had a chromosome abnormality different from trisomy 21. Considering the total population surveyed, trisomy 18 was detected in 1:6,099; trisomy 13 was seen in 1:24,397 and unbalanced rearrangements were found in 1:7,319 infants. Those rates were not significantly different from the expected ones, as compared to previous cytogenetic surveys of consecutive births. We concluded that most chromosome abnormalities associated with congenital malformations can be detected at low cost, provided there is a high accuracy of clinical examination and referral criteria, as well as close cooperation between pediatricians and geneticists.
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