RESUMO
BACKGROUND: Intrachromosomal amplification of chromosome 21 (iAMP21) is known to be associated with poor prognosis in B-cell ALL (B-ALL). To determine the frequency and clinical characteristics of iAMP21 in Korean B-ALL patients, we performed FISH and multiplex ligation-dependent probe amplification (MLPA) analyses. METHODS: A total of 102 childhood B-ALL patients were screened with ETV6-RUNX1 FISH probes (Abbott Molecular, USA). The presence of an iAMP21 was confirmed by using MLPA P327 iAMP21-ERG probemix (MRC Holland, The Netherlands). RESULTS: iAMP21 was detected in one of the screened B-ALL patients (1/102 patients, 1.0%) who presented the ALL immunophenotype and complex karyotype at initial diagnosis. The patient relapsed twice after bone marrow transplantation. MLPA showed 12.5-Mb and 4.28-Mb regions of amplification and deletion, respectively. CONCLUSIONS: The frequency of iAMP21 is considerable in Korean pediatric patients. Our report suggests that iAMP21 in childhood B-ALL has very unfavorable impact on patient's prognosis. Additional methods such as MLPA analysis is essential to rule out patients with equivocal interphase FISH results.
Assuntos
Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Adulto Jovem , Povo Asiático/genética , Linfócitos B/metabolismo , Cromossomos Humanos Par 21 , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Sondas de DNA/metabolismo , Imunofenotipagem , Hibridização in Situ Fluorescente , Reação em Cadeia da Polimerase Multiplex , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Repressoras/genética , República da Coreia , Translocação GenéticaRESUMO
BACKGROUND: Specific cytogenetic aberrations detected by conventional karyotyping or FISH play a major role in the diagnosis, prognosis, and treatment of patients with acute leukemia. The FISH technique enhances the capacity of conventional karyotyping to detect subtle chromosomal aberrations. Multiprobe FISH assay (Cytocell, UK) can hybridize multiple probes to a single slide, thereby increasing the detection rate of cytogenetic aberrations. This study aimed to evaluate multiprobe FISH in detecting cytogenetic abnormalities in acute leukemia. METHODS: Thirty newly diagnosed acute leukemia patients who attended the hematology clinic at Dong-A University Hospital from October 2008 to October 2012 were enrolled in the study. The multiprobe FISH results were compared with those of G-banding. RESULTS: Multiprobe FISH detected the chromosomal aberrations identified by G-banding, as well as additional aberrations in 6 of 30 (20.0%) cases, which included ETV6/RUNX1 translocation, p16 deletion, TP53 deletion, and IGH break-apart. CONCLUSIONS: The multiprobe FISH assay was a more sensitive and reliable technique compared with G-banding. It was also more cost-effective and yielded faster results.
Assuntos
Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Doença Aguda , Bandeamento Cromossômico , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Deleção de Genes , Hibridização in Situ Fluorescente , Cariotipagem , Leucemia/diagnóstico , Leucemia Mieloide Aguda/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Repressoras/genética , Translocação Genética , Proteína Supressora de Tumor p53/genéticaRESUMO
BACKGROUND: TEL (ETV6)/AML1 (RUNX1) rearrangement is observed in approximately 20-25% of childhood precursor B-ALL and is associated with a favorable outcome. Additional genetic changes, associated with TEL/AML1, are frequently found. We evaluated the prevalence and prognostic significance of TEL/AML1 rearrangement and additional genetic changes in the TEL and AML1 genes in Korean childhood precursor B-ALL. METHODS: We performed FISH using LSITEL/AML1 ES probe (Vysis, USA) in 123 children diagnosed as having precursor B-ALL and assessed clinical relevance of the TEL/AML1 rearrangement and additional genetic abnormalities. RESULTS: The frequency of TEL/AML1 was 17.1% (21/123) in patients with precursor B-ALL. TEL/ AML1-positive group showed male predominance (P=0.012) and younger age of onset than TEL/ AML1-negative group by 1.6 yr (P=0.013). The outcome of TEL/AML1-positive group tended to show lower incidences of relapse (1/21 vs 20/102), death (1/21 vs 17/102) and longer event free survival. Among TEL/AML1-positive patients, unrearranged TEL deletion, AML1 gain, and unrearranged TEL deletion combined with AML1 gain were detected in 61.9%, 23.8%, and 9.5%, respectively. There were no significant differences in the clinical features and outcome according to the presence or absence of additional genetic changes. CONCLUSIONS: The frequency of TEL/AML1 and additional genetic changes in TEL and AML1 is higher than previous studies in Korean children, and in close agreement with usually reported one, 20-25%. TEL/AML1-positive group showed a tendency toward better prognosis. Further study is needed to clarify the prognostic significance of additional changes in TEL and AML1 based on a large sample size.