Cytogenetic analysis of 100 consecutive newly diagnosed cases of acute lymphoblastic leukemia in Rio de Janeiro

Cytogenetic abnormalities and TP53 and RAS gene profiles of childhood acute lymphoblastic leukemia in Morocco

BACKGROUND

Recurrent genetic abnormalities affecting pivotal signaling pathways are the hallmark of childhood acute lymphoblastic leukemia (ALL). The identification of these aberrations remains clinically important. Therefore, we sought to determine the cytogenetic profile and the mutational status of TP53 and RAS genes among Moroccan childhood cases of ALL.

METHODS

In total, 35 patients with childhood ALL were enrolled in the study. The diagnosis and treatment were established in the Pediatric Hematology and Oncology Center at the Children's Hospital of Rabat. Chromosome banding analysis and fluorescence in situ hybridization were used to detect genetic aberrations. Blood samples were screened for TP53 and RAS mutations using Sanger sequencing.

RESULTS

Of the 35 cases, 30 were B-lineage ALL (85.7 %). Moreover, a male predominance was observed. Cytogenetic analysis revealed chromosomal anomalies in 27 cases (77.1 %). The most frequent aberrations were high hyperdiploidy and BCR/ABL rearrangement. Interestingly, we found the rare t(15;16) and the t(8;14), which are uncommon translocations in pediatric B-ALL. The mutational analysis revealed Pro72Arg (rs1042522:C > G) and Arg213Arg (rs1800372:A > G) in TP53. In correlation with cytogenetic data, rs1042522:C > G showed a significant association with the occurrence of chromosomal translocations (p = 0.04). However, no variant was detected in NRAS and KRAS genes.

CONCLUSION

Our findings emphasize the significance of detecting chromosomal abnormalities as relevant prognostic markers. We also suggest a low occurrence of genetic variants among Moroccan children with ALL.

Study of the Chromosomal Abnormalities and Associated Complex Karyotypes in Hematological Cancer in the Population of West Bengal: A Prospective Observational Study

Introduction Chromosomal instability is an important feature of hematological cancer. The pathogenesis is complex and it involves genetic and epigenetic factors. As a genetic factor, chromosomal instability may play a key role in leukemogenesis. Accumulation of genetic alteration is mainly responsible for numerical and structural chromosomal rearrangement or clonal evaluation. But disease progression is often driven by chromosomal translocation, hyper- or hypodiploidy with structural abnormalities, and complex karyotypes.

Objective This research aimed to study the different types of chromosomal abnormalities in clinically suspected hematological cancer patients.

Materials and Methods Cytogenetic analysis was performed based on phytohemaglutinin stimulated peripheral blood lymphocyte cultures and bone marrow culture, without mitogen, of the respective patients of West Bengal from March 2016 to February 2018. All clinically suspected hematological cancer patients referred for karyotyping to the institutional genetics department have been included without any biasness of sex and age. Karyotypes were described according to the International System for Cytogenetic Nomenclature (ISCN 2005).

Results In the present study, 56 clinically suspected hematological cancer cases were observed and 41 cases of chromosomal rearrangement were found which clearly show chromosomal instability as the main driving force for hematological cancer transformation. Presence of variant Philadelphia chromosomes with classical translocation, mosaic complex karyotypes, variable numerical, and structural chromosomal abnormality, along with severe-to-moderate hypo- and hyperdiploidy, and presence of marker chromosomes were the main findings of this study.

Conclusion The result shows that the detection of chromosomal instability was important for preliminary diagnosis, treatment, prognosis, and further management. So the present study provided additional information about chromosomal instability in hematological cancer at Kolkata and adjoining regions.

Altered neutrophil immunophenotypes in childhood B‑cell precursor acute lymphoblastic leukemia

An increasing number of evidences suggest a genetic predisposition in acute lymphoblastic leukemia (ALL) that might favor the occurrence of the driver genetic alterations. Such genetic background might also translate into phenotypic alterations of residual hematopoietic cells. Whether such phenotypic alterations are present in bone marrow (BM) cells from childhood B-cell precursor (BCP)-ALL remains to be investigated. Here we analyzed the immunophenotypic profile of BM and peripheral blood (PB) maturing/matured neutrophils from 118 children with BCP-ALL and their relationship with the features of the disease. Our results showed altered neutrophil phenotypes in most (77%) BCP-ALL cases. The most frequently altered marker was CD10 (53%), followed by CD33 (34%), CD13 (15%), CD15/CD65 (10%) and CD123 (7%). Of note, patients with altered neutrophil phenotypes had younger age (p = 0.03) and lower percentages of BM maturing neutrophils (p = 0.004) together with greater BM lymphocyte (p = 0.04), and mature B-cell (p = 0.03) counts. No significant association was found between an altered neutrophil phenotype and other disease features. These findings point out the potential existence of an altered residual hematopoiesis in most childhood BCP-ALL cases.

Banding cytogenetic analysis in pediatric patients with acute lymphoblastic leukemia (ALL) in a Brazilian population

BACKGROUND

Cytogenetic studies in Brazilian population about childhood acute lymphoblastic leukemia (ALL), the most common childhood malignancy, are scarce. Moreover, Brazilian race is very heterogeneous and is made by the confluence of people of several different origins, from the original Native Brazilians, with the influx of Portuguese colonizers, Black African slaves, and recent European, Arab and Japanese immigration. The purpose of this prospective, multicentric study was to assess the sociodemographic, clinic and cytogenetic characteristics of the children treated for ALL in the Northeast region of Brazil.

RESULTS

This study includes thirty patients between 4 months and 17 years old treated for ALL from January 1st, 2009 to November 30th, 2010. Cytogenetic analysis showed that in nineteen out of thirty patients (64%) presented some chromosome abnormalities, in which 53% corresponds to numerical abnormalities, 21% structural and numerical abnormalities, and 26% only structural changes. Moreover, seven patients presented complexes karyotype not yet described in the literature. Taken together these results show the importance of the cytogenetic analysis in ALL pediatric patients and illustrates that the studied population presented unexpected complexes karyotypes which were correlated to poor outcome.

CONCLUSION

The results demonstrate the importance of banding cytogenetics for ALL diagnosis despite the use of most modern techniques such as FISH and aCGH, and provide reliable insight into the ALL in Brazil.

A comprehensive cytogenetic classification of 1466 Chinese patients with de novo acute lymphoblastic leukemia

Cytogenetics and molecular cytogenetics of 1466 Chinese patients with de novo acute lymphoblastic leukemia (ALL) were studied. Cytogenetic results were available in 1175 patients. Cross-correlations of 23 subclasses of cytogenetic abnormalities were described. Childhood cases had higher incidences of normal karyotype, t(1;19), +8, 12q-, +21, +22 and high hyperdiploidy with 51-65 chromosomes, and lower incidences of t(9;22) and -5/5q- than adult ones (all p<0.05). Relationships of cytogenetic subclasses with immunophenotyping subgroups of ALL were studied. Our study presents the cytogenetic characteristics of a large series of Chinese ALL patients.

Cytogenetic characterization of childhood acute lymphoblastic leukemia in Nicaragua

BACKGROUND

Within the frame of a twinning programme with Nicaragua, The La Mascota project, we evaluated in our study the contribution of cytogenetic characterization of acute lymphoblastic leukemia (ALL) as prognostic factor compared to clinical, morphological, and immunohistochemical parameters.

METHODS

All patients with ALL treated at the only cancer pediatric hospital in Nicaragua during 2006 were studied prospectively. Diagnostic immunophenotyping was performed locally and bone marrow or blood samples were sent to the cytogenetic laboratory of Zurich for fluorescence in situ hybridization (FISH) analysis and G-banding.

RESULTS

Sixty-six patients with ALL were evaluated. Their mean age at diagnosis was 7.3 years, 31.8% were >or=10 years. Thirty-four patients (51.5%) presented with hyperleucocytosis >or=50 x 10(9)/L, 45 (68.2%) had hepatosplenomegaly. Immunophenotypically 63/66 patients (95%) had a B-precursor, 2 (3%) a T- and 1 (1.5%) a B-mature ALL. FISH analysis demonstrated a TEL/AML1 fusion in 9/66 (14%), BCR/ABL fusion in 1 (1.5%), MLL rearrangement in 2 (3.1%), iAMP21 in 2 (3.1%), MYC rearrangement in 1 (1.5%), and high-hyperdiploidy in 16 (24%). All patients but two with TEL/AML1 fusion and high-hyperdiploidy were clinically and hematologically in the standard risk group whereas those with poor cytogenetic factors had clinical high-risk features and were treated intensively.

CONCLUSIONS

Compared to Europe, the ALL population in Nicaragua is older, has a higher proportion of poor prognostic clinical and hematological features and receives more intensive treatment, while patients with TEL/AML1 translocations and high-hyperdiploidy are clinically in the standard risk group. Cytogenetics did not contribute as an additional prognostic factor in this setting.

Fatores prognósticos em crianças e adolescentes com Leucemia Linfóide Aguda

OBJETIVOS: descrever características clínico-laboratoriais, determinar taxas de resposta ao tratamento e identificar fatores de risco que influenciaram na sobrevida de pacientes pediátricos com leucemia linfóide aguda (LLA). MÉTODOS: estudo retrospectivo do tipo série de casos com 108 pacientes de idade até 18 anos, admitidos para tratamento de LLA na Fundação de Hematologia e Hemoterapia de Pernambuco (HEMOPE), Brasil, de janeiro de 1993 a dezembro de 2001. As variáveis analisadas foram: sexo, idade, principais sintomas e sinais, leucometria, imunofenótipo e grupo de risco ao diagnóstico, taxas de remissão e recaída, óbito e sobrevida global, local de recaída e fatores de risco para a sobrevida. Medidas descritivas foram usadas para a análise estatística. O tempo de sobrevida dos pacientes foi estimado através da função de sobrevida de Kaplan-Meier e Log-Rank. O efeito de fatores de risco no tempo de sobrevida foi avaliado através do Modelo de Regressão de Cox. RESULTADOS: foi encontrada a relação masculino:feminino de 1,7:1, mediana de idade ao diagnóstico de oito anos, freqüência de queixas músculo-esqueléticas (51%), infiltração do sistema nervoso central (8%), LLA-Precursor B (81%) e LLA-T (19%). A distribuição dos grupos correspondeu a Risco Básico Verdadeiro (12%), Risco Básico (21%) e Alto Risco (67%). As principais taxas foram: remissão (86%), óbitos na indução (5,5%), recaída (24%) e sobrevida global (62,5%). CONCLUSÕES: a variável de impacto na sobrevida foi a leucometria. A taxa de sobrevida global foi influenciada pela freqüência elevada de pacientes considerados de alto risco.

Cytogenetic Profile of Childhood Acute Lymphoblastic Leukemia in Oman

BACKGROUND

Chromosomal abnormalities have important diagnostic and prognostic significance in acute lymphoblastic leukemia (ALL). The purpose of this study was to define and classify the frequency and type of chromosomal abnormalities among newly diagnosed children with ALL and compare the results with those reported from other geographical regions of the world.

METHODS

Bone marrow chromosomal studies with GTG banding were performed in untreated ALL pediatric patients aged from 7 days to 14 years.

RESULTS

Among Omani children examined with ALL, 47 (81%) patients yielded results, with 26 (55.3%) showing an abnormal karyotype [10 (21.3%) pseudodiploid, 2 (4.3%) hypodiploid and 14 (29.7%) hyperdiploidy] and 21 (44.6%) had normal diploidy. Structural abnormalities were observed in 16 (34%), of which 11 (23.4%) cases were translocations, the most frequent being t(9;22) observed in three (6.4%) of our patients. Uncommon translocations such as t(9;15)(p11;q10), t(3;6)(p12;q11), t(1;6)(?31;?q23), t(1;19)(q12;q12), der(18)t(12;18)(q11;p11), and other structural aberrations add(2)(q22), add(6)(q16), add(18)(q22), add(14)(q32) along with deletions del(10)(q22), del(12)(p11), del(12)(p12), del(18)(q11) were also observed.

CONCLUSIONS

The study showed a good correlation and concordance between the ploidy distribution by cytogenetics and flow cytometry. The patterns of chromosomal anomalies in our patients showed some variations in the frequency of aberrations reported. It is therefore necessary that newer techniques like fluorescence in situ hybridization (FISH) along with reverse transcriptase polymerase chain reaction (RT-PCR) and spectral karyotyping will help us identify chromosomal aberrations not detected by conventional cytogenetic methods in the near future. To our knowledge, this is the first report from the Middle East of a cytogenetic study on childhood ALL.

Translocation (10;17)(p15;q21) is a recurrent anomaly in acute myeloblastic leukemia

We report here two cases of patients with acute myeloblastic leukemia, type M1 (FAB classification), associated with a t(10;17)(p15;q21). Fluorescence in situ hybridization with the LSI PML/RARA dual-color probe showed the breakpoint to be distal to the RARA locus. Four other patients with this translocation have been reported, three of them having acute undifferentiated or poorly differentiated leukemia.