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ORIGINAL ARTICLE
Year : 2020  |  Volume : 10  |  Issue : 4  |  Page : 234-239  

Molecular detection of fusion oncogenes in zambian patients with acute lymphoblastic leukemia


1 Department of Pathology and Microbiology, School of Medicine, University of Zambia; Department of Pathology and Microbiology, University Teaching Hospital, Lusaka, Zambia
2 Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka, Zambia
3 Department of Pathology and Microbiology, University Teaching Hospital, Lusaka, Zambia

Date of Submission24-May-2019
Date of Decision25-May-2020
Date of Acceptance11-Jun-2020
Date of Web Publication04-Oct-2020

Correspondence Address:
Pauline Okuku
Department of Pathology and Microbiology, School of Medicine, University of Zambia, P. O. Box: 50110, Lusaka 15101
Zambia
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijabmr.IJABMR_179_19

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   Abstract 


Introduction: Chromosomal aberrations play a significant role in the pathogenesis of acute lymphoblastic leukemia (ALL) with prognostic and therapeutic implications. Despite the availability of molecular tools, low-resource settings struggle to diagnose the disease due to limited diagnostic capacity. The objective of this study was to detect common chromosomal aberrations in patients with ALL attending the University Teaching Hospital (UTH) in Lusaka, Zambia. Materials and Methods: In this prospective study, 19 blood samples from patients with ALL were screened for the presence of BCR-ABL, E2A-PBX1, MLL-AF4, and ETV6-RUNX1 fusion oncogenes using reverse transcriptase-polymerase chain reaction assay. Blood counts and clinical characteristics of patients were also assessed. Results: The age of patients ranged from 1½ to 72 years and comprised 57.9% of males and 42.1% of females. The majority of these patients were children (68%), and adults only comprised 32%. Only BCR-ABL and E2A-PBX1 oncogenes were detected in 3/19 of cases. The BCR-ABL gene was detected in a 4-year-old female child and a 15-year-old child. Both cases were associated with hepatomegaly and anemia coupled with low hemoglobin, white blood cell, and platelet counts. E2A-PBX1 was detected in a 12-year-old child with lymphadenopathy and splenomegaly, coupled with low hemoglobin, white blood cell, and platelet counts. All the three patients who harbored these fusion oncogenes died. Conclusion: This is the first study from Zambia to investigate the presence of fusion oncogenes in leukemia patients, which were found only among the older children population. Based on these findings, we recommend that molecular diagnosis be made a priority for the younger leukemia patient population at UTH.

Keywords: Acute lymphoblastic leukemia, fusion oncogenes, reverse transcriptase-polymerase chain reaction, Zambia


How to cite this article:
Okuku P, Kwenda G, Samutela M, Nkhoma P, Mantina H. Molecular detection of fusion oncogenes in zambian patients with acute lymphoblastic leukemia. Int J App Basic Med Res 2020;10:234-9

How to cite this URL:
Okuku P, Kwenda G, Samutela M, Nkhoma P, Mantina H. Molecular detection of fusion oncogenes in zambian patients with acute lymphoblastic leukemia. Int J App Basic Med Res [serial online] 2020 [cited 2020 Dec 2];10:234-9. Available from: https://www.ijabmr.org/text.asp?2020/10/4/234/297249




   Introduction Top


Acute lymphoblastic leukemia (ALL) is a malignant disease most common in children and accounts for about 80% of all pediatric leukemia cases.[1] It is less common in adults and represents about 12% of all leukemia cases in this group.[2],[3] It is characterized by an accumulation of malignant immature lymphoid cells in the bone marrow.[4] Genetic studies have identified a number of aneuploidies and chromosomal aberrations associated with ALL.[5],[6] These genetic abnormalities play a critical role in the prognosis and treatment of the disease.[6],[7]

Previous studies have shown that ALL is a heterogeneous disease with different clinical and genetic abnormalities in different ethnic groups.[8],[9] This suggests that the distribution of genetic lesions of ALL may not be the same among different ethnic groups. It is, therefore, important to understand the biology of the disease, including the molecular mechanisms involved, in order to provide appropriate treatment to affected populations. In limited-resource countries such as Zambia, the management of ALL proves to be a challenge because of limited diagnostic and treatment capacity. For diagnosis of ALL, the World Health Organization recommends the use of molecular methods for the detection of genetic lesions.[10] At the University Teaching Hospital (UTH) in Lusaka, Zambia, the current diagnostic approach for leukemia involves only clinical and cell morphological assessments. The use of this approach implies that most of the cases are not correctly diagnosed, thereby rendering physicians to manage patients inappropriately. This study was, therefore, aimed at detecting common chromosomal aberrations in ALL patients attending the UTH.


   Materials and Methods Top


Patients and samples

This was a prospective study in which 19 blood samples were obtained from both male and female patients with ALL being managed at the Onco-Haematology Clinic of the UTH in Lusaka, Zambia, for diagnostic purposes. These samples were received in the hospital Haematology Laboratory between July 2015 and April 2016 as part of the routine laboratory analyses. Four milliliters of blood was collected from each patient in an EDTA vacutainer through venepuncture. Patients were excluded if they had acute myeloid leukemia or severe systemic illness. Data on demographics, medical history, clinical manifestations, and symptoms for each patient were abstracted from medical records at the hospital. Physicians performed all the physical examinations on the patients.

Full blood count analysis and peripheral blood examination

Full blood counts were performed on the Sysmex XT 4000i Hematology Analyzer (Sysmex Corporation, Japan). For preparation of blood smears, a drop of blood was placed on one end of a clean glass slide then a smear of a single layer of cells was made using a glass spreader held at a 45 degrees angle. The blood film was then air-dried and labeled on the frosted end of the slide. The film was fixed in absolute methanol for 5 min and then transferred into a jar of May-Grunwald stain (Merck, California, USA) freshly diluted with an equal volume of 0.1M Söresen's phosphate buffer (pH 7.2–7.4). The film was then allowed to stain for 15 min and then transferred into a jar of Giemsa's stain (Merck, California, USA) freshly diluted with 4 volumes of the Söresen's phosphate buffer for 15 min. The slide was then transferred into a jar of fresh buffer for 5 min and allowed to air-dry. The film was finally examined under a microscope for malignant cells by a qualified hematologist as a means of determining the ALL phenotype.

Detection of chromosomal aberrations

RNA extraction

Total RNA was extracted from whole blood using a QIAamp RNA Blood Mini Kit (Qiagen, Hilden, Germany) according to the manufacturer's instructions.

Synthesis of complementary DNA and polymerase chain reaction amplification

Reverse transcription and polymerase chain reaction (PCR) amplification were performed in the same tube using the AgPath-ID One-Step RT-PCR Kit (Applied Biosystems, Foster City, CA, USA) which simultaneously converts RNA into complementary DNA and performs DNA amplification. Briefly, 2 μl of RNA was added to 23 μl of PCR master mix containing 12.5 μl 2X RT-PCR buffer (Applied Biosystems, Foster City, CA, USA), 1 μl 25X PCR Enzyme Mix (Applied Biosystems, Foster City, CA, USA), 4.5 μl water, and 2.5 μl of 5 μM of each pair of the primers targeting one of the four fusion ALL genes: E2A-PBX1, MLL-AF4, BCR-ABL (p190), or TEL-AML1 [Table 1]. The reverse transcriptase reaction was carried out at 45°C for 10 min, followed by inactivation and initiation denaturation at 95°C for 10 min. For DNA amplification, the reaction tube was first heated to 95°C for 10 min and then subjected to 40 cycles of amplification at 94°C for 30 s, 68°C for 30 s, and 72°C for 1 min. This was finally followed by a 10-min extension step at 72°C and holding at 4°C on a GeneAmp 2700 PCR thermocycler (Applied Biosystems, Foster City, CA, USA). The presence of amplified products was detected by electrophoresis of 5 ml of the amplicon on a 1.5% SeaKem LE agarose gel ( Lonza, Rockland, ME, USA). After electrophoresis, the gels were imaged on a Biotop SC-645 Gel Documentation System (Biotech Co. Ltd., Shanghai, China). The expected gene fusion product sizes are shown in [Table 1].
Table 1: Fusion oncogene targets and primers used in the multiplex polymerase chain reaction assays

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Ethics approval

All specimens were de-identified and given study-specific identification codes. Informed consent was obtained in a local language from a parent or legal guardian of the children and adult patients. Permission to conduct the study was sought from the UTH Management in Lusaka, Zambia, while ethics clearance was obtained from the University of Zambia Biomedical Research Ethics Committee (Clearance Certificate Number 005-06-15).


   Results Top


Patient characteristics

Out of the 19 cases enrolled in the study, 57.9% (11/19) were male, while 42.1% (8/19) were female [Table 2]. The male-to-female ratio was 1.4:1. The age for the patients was from 1½ to 72 years, with a median age of 14. The majority of patients were children (68%, 13/19) and adults comprised only 32% (6/19). Children were defined as patients aged 15 years and below. Males among the children comprised 46% (6/13), while females were 54% (7/13). In the adult category, 83% (5/6) were male, while only one was a female.
Table 2: Correlation of clinical characteristics of patients to genetic alterations

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The main clinical features identified among the patients were fever, hepatomegaly, lymphadenopathy, splenomegaly, and anemia. The proportion of patients with fever was 36.8% (7/19), the majority of which were children (85.7%, 6/7) and only one adult (14.3%, 1/7). Hepatomegaly was seen in 26.3% (5/19) of the patients, all of which were children. Lymphadenopathy occurred in 15.8% (3/19) of the patients, and this was only seen in children. Splenomegaly was seen in 10.5% (2/19) of the patients: one female child and one male adult. Anemia occurred in 52.6% (10/19) of the patients, and 60% (6/10) of which were children. The remaining 40% (4/10) were adults [Table 2]. They all presented with normocytic normochromic anemia. The majority of the participants presented with high white blood cell counts, low levels of hemoglobin, and low platelet counts. White blood cell counts ranged from 0.24 to 657 × 109/l (mean value, 131 × 109/l) and platelet counts ranged from 7 to 289 × 109/l (mean value, 99.6 × 109/l), while that of hemoglobin levels ranged from 2.2 to 13 g/dl (mean value, 6.4 g/dl). Leukocytosis was detected in 63.2% (12/19) of the patients, while the proportion with leukopenia and pancytopenia and thrombocytopenia was 26.3% (5/19) and 68.4% (13/19), respectively [Figure 1].
Figure 1: Laboratory findings of suspected acute lymphoblastic leukemia cases at diagnosis

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Detection of fusion oncogenes

Only two fusion oncogenes, BCR-ABL (p190) and E2A-PBX1, were detected in three different patients (15.8%, 3/19) by the reverse transcriptase-PCR [Figure 2]. BCR-ABL was detected in two of the 19 (10.5%) patients: one in a 4-year-old female child, while the other one in another child male child aged 15 years who had fever, hepatomegaly, and anemia with low hemoglobin level (4.5 g/dl), white blood cell count (1.73 × 109/l), and platelet (13 × 109/l) count. E2A-PBX1 was detected only in one 12-year male child (5.3%) with fever and hepatomegaly and also low hemoglobin (6.9 g/dl), white blood cell (0.24 × 109/l), and platelet (53 × 109/l) counts. Lymphadenopathy and splenomegaly occurred only in patients who did not have detectable ALL fusion oncogenes [Table 2]. All the patients who harbored these fusion oncogenes died.
Figure 2: Detection of fusion genes; A representative gel electrophoresis showing samples positive for gene fusion. M, 100 bp marker; 1, positive control; 2 and 3, samples positive for BCR/ABL (p190) gene fusion; 4, sample positive for E2A/PBX1 fusion gene and 5, negative control

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   Discussion Top


Molecular genetic abnormalities and the cytogenetic features of leukemic cells are highly prognostic of treatment outcome, permitting more precise risk assessment of this disease in order to avoid overtreatment or undertreatment of individual patients.[11]

This study showed that there were more male than female patients, and this was in line with studies from other countries. A study conducted in southern India showed a male-to-female ratio of 1.6:1, while a similar study conducted in China reported a 1.84:1 male-to-female ratio.[12],[13] The reason for the observed male preponderance of the ALL cases is unclear. Most of the cases were associated with children, and this finding is consistent with findings in other countries. Similar studies conducted in the United States and India demonstrated that the incidence of ALL was higher in children and adolescents under 15 years of age than in individuals above this age.[14],[15]

Fever, anemia, and hepatomegaly were the predominant clinical manifestations at presentation. Other manifestations presented included lymphadenopathy and splenomegaly, but these were not associated with cases. Laboratory findings also showed high levels of leukemic cells which resulted in most of the patients having high white blood cell count, low hemoglobin level, and low platelet count. A study conducted in Brazil showed that hepatomegaly, splenomegaly, fever, and lymphadenopathy were the most frequent clinical features among ALL patients.[16] A similar study carried out in India showed that hepatosplenomegaly and lymphadenopathy were ranked higher than other clinical features.[17]

Molecular genetic abnormalities and the cytogenetic features of leukemic cells are highly prognostic of treatment outcome, permitting more precise risk assessment of individual patients.[18] Our results show that two of the children harbored the BCR-ABL1 fusion oncogene (t9;22). Previous studies have shown that the most frequent chromosomal translocation in older children and adults is t (9;22).[19],[20] A study conducted in Guatemala showed that the incidence of BCR-ABL transcript was high, accounting for 7% of the cases among older children aged between 5 and 14 years.[21] The explanation for the association between this gene fusion and this age group could be as a result of the fact that the incidence of the BCR-ABL gene transcript increases with age from approximately 3% of children with ALL up to approximately 25% in adult ALL cases.[22]

The only other fusion oncogene detected was E2A-PBX1, and this was detected a 12-year-old child. Similar studies conducted in Guatemala and Mexico showed a low prevalence of this oncogene.[21],[23],[24] However, in our study, we cannot arrive at this conclusion as our sample size was relatively small compared with other studies. The transcript resulting from this gene fusion leads to the expression of chimeric transcription factors that block differentiation and apoptosis of cells by interfering with the function of their wild-type counterparts.[25]

Both BCR-ABL1 and E2A-PBX1 fusion transcripts have been found to be associated with poor prognoses at all ages.[26],[27],[28] ALL patients with these fusion gene transcripts often present with aggressive leukemia that is resistant to standard therapies resulting in high relapse rates.[29] It is worth noting that in our study, the patients who were positive for these fusion genes died in the course of the study. However, many factors could have contributed to their death, one of which could be attributed to the poor outcomes associated with these gene fusions.

Other fusion oncogenes, MLL-AF4 and ETV6-RUNX1, were not detectable in our patients. This could be attributed to the fact that MLL-AF4 is more prevalent among infants <6 months of age,[30] but our study had patients older than this age. It has been documented that ETV6/RUNX1 is the most common genetic lesion in childhood ALL,[31] but we did not detect this oncogene in our study. The probable explanation for this is that our sample size was small. However, patients harboring this oncogene have been shown to respond favorably to treatment.[32]


   Conclusion Top


This is the first study from Zambia to investigate the presence of leukemia fusion oncogenes among ALL patients and provides some baseline data for the country. Studies from other countries have indicated that molecular evaluation of ALL at diagnosis and its integration with clinical characteristics can improve patient outcome through the intensification of treatment protocols.[33],[34] More comprehensive and large-scale studies using molecular tools such as real-time PCR and whole-genome sequencing are needed to detect more cases of ALL or other leukemia cases in order to enhance the identification of genetic lesions and contribute to the improved management of affected patients.

Acknowledgments

The authors would like to thank the nursing, clinical, and laboratory staff of the UTH in Lusaka, Zambia, for facilitating the collection of the blood samples; Professor Paul Kelly of the Tropical Gastroenterology and Nutrition Group at the University of Zambia School of Medicine for providing some vital reagents for this project; and the management of the UTH for providing laboratory space for this work.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Nasedkina T, Zasedatelev A, Samochatova E, Guseva N, Gra O, Yatsenko Y. Diagnostics of Molecular Markers in Childhood Acute Leukaemia Using Biochips. Intech Open Access Publisher; 2011. Accessed from: https://www.intechopen.com/ books/acute-leukemia-the-scientist-s-perspective-and-challenge/ diagnostics-of-molecular-markers-in-childhood-acute-leukaemia-using-biochips. [Last accessed on 2020 Jul 08].  Back to cited text no. 1
    
2.
Redaelli A, Laskin BL, Stephens JM, Botteman MF, Pashos CL. A systematic literature review of the clinical and epidemiological burden of acute lymphoblastic leukaemia (ALL). Eur J Cancer Care (Engl) 2005;14:53-62.  Back to cited text no. 2
    
3.
Grigoropoulos NF, Petter R, Van 't Veer MB, Scott MA, Follows GA. Leukaemia update. Part 1: Diagnosis and management. BMJ 2013;346:f1660.  Back to cited text no. 3
    
4.
Harrison CJ. Acute lymphoblastic leukemia. Clin Lab Med 2011;31:631-47, ix.  Back to cited text no. 4
    
5.
Moorman AV. The clinical relevance of chromosomal and genomic abnormalities in B-cell precursor acute lymphoblastic leukaemia. Blood Rev 2012;26:123-35.  Back to cited text no. 5
    
6.
Advani AS. New immune strategies for the treatment of acute lymphoblastic leukemia: Antibodies and chimeric antigen receptors. Hematology Am Soc Hematol Educ Program 2013;2013:131-7.  Back to cited text no. 6
    
7.
Gu J, Reynolds A, Fang L, DeGraffenreid C, Sterns K, Patel KP, et al. Coexistence of iAMP21 and ETV6-RUNX1 fusion in an adolescent with B cell acute lymphoblastic leukemia: Literature review of six additional cases. Mol Cytogenet 2016;9:84.  Back to cited text no. 7
    
8.
Harvey RC, Mullighan CG, Chen IM, Wharton W, Mikhail FM, Carroll AJ, et al. Rearrangement of CRLF2 is associated with mutation of JAK kinases, alteration of IKZF1, Hispanic/Latino ethnicity, and a poor outcome in pediatric B-progenitor acute lymphoblastic leukemia. Blood 2010;115:5312-21.  Back to cited text no. 8
    
9.
Yang JJ, Cheng C, Devidas M, Cao X, Fan Y, Campana D, et al. Ancestry and pharmacogenomics of relapse in acute lymphoblastic leukemia. Nat Genet 2011;43:237-41.  Back to cited text no. 9
    
10.
Vardiman JW, Thiele J, Arber DA, Brunning RD, Borowitz MJ, Porwit A, et al. The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: Rationale and important changes. Blood 2009;114:937-51.  Back to cited text no. 10
    
11.
Pui CH, Carroll WL, Meshinchi S, Arceci RJ. Biology, risk stratification, and therapy of pediatric acute leukemias: An update. J Clin Oncol 2011;29:551-65.  Back to cited text no. 11
    
12.
Sudhakar N, Rajalekshmy KR, Rajkumar T, Nancy KN. RT-PCR and real-time PCR analysis of E2A-PBX1, TEL-AML1, mBCR-ABL and MLL-AF4 fusion gene transcripts in de novo B-lineage acute lymphoblastic leukaemia patients in south India. J Genet 2011;90:349-53.  Back to cited text no. 12
    
13.
Li SY, Ye JY, Meng FY, Li CF, Yang MO. Clinical characteristics of acute lymphoblastic leukemia in male and female patients: A retrospective analysis of 705 patients. Oncol Lett 2015;10:453-8.  Back to cited text no. 13
    
14.
Howlader N, Noone AM, Krapcho M, Garshell J, Neyman N, Altekruse SF, et al, editors. SEER Cancer Statistics Review, 1975-2010. National Cancer Institute; Bethesda, MD. Available from: http://seer.cancer.gov/csr/1975_2010/, based on November 2012 SEER data submission, posted to the SEER web site, April 2013.  Back to cited text no. 14
    
15.
Bhutani M, Kochupillai VI, Bakshi S. Childhood acute lymphoblastic leukemia: Indian experience. Indian J Med Paediatr Oncol 2004;20:3-8.  Back to cited text no. 15
    
16.
Lustosa de Sousa DW, de Almeida Ferreira FV, Cavalcante Félix FH, de Oliveira Lopes MV. Acute lymphoblastic leukemia in children and adolescents: Prognostic factors and analysis of survival. Rev Bras Hematol Hemoter 2015;37:223-9.  Back to cited text no. 16
    
17.
Harrison CJ. The detection and significance of chromosomal abnormalities in childhood acute lymphoblastic leukaemia. Blood Rev 2001;15:49-59.  Back to cited text no. 17
    
18.
Braziel R, Shipp M, Feldman A, Espina V, Winters M, Jaffe E, et al. Molecular diagnostics. Hematol Am Soc Hematol Educ Program 2003;279-293:1520-4391.  Back to cited text no. 18
    
19.
Olde Nordkamp L, Mellink C, van der Schoot E, van den Berg H. Karyotyping, FISH, and PCR in acute lymphoblastic leukemia: Competing or complementary diagnostics? J Pediatr Hematol Oncol 2009;31:930-5.  Back to cited text no. 19
    
20.
Teitell MA, Pandolfi PP. Molecular genetics of acute lymphoblastic leukemia. Annu Rev Pathol 2009;4:175-98.  Back to cited text no. 20
    
21.
Carranza C, Granados L, Morales O, Jo W, Villagran S, Tinti D, et al. Frequency of the ETV6-RUNX1, BCR-ABL1, TCF3-PBX1, and MLL-AFF1 fusion genes in Guatemalan pediatric acute lymphoblastic leukemia patients and their ethnic associations. Cancer Genet 2013;206:227-32.  Back to cited text no. 21
    
22.
Hunger SP, Mullighan CG. Acute Lymphoblastic Leukemia in Children. N Engl J Med 2015;373:1541-52.  Back to cited text no. 22
    
23.
Bekker-Méndez VC, Miranda-Peralta E, Núñez-Enríquez JC, Olarte-Carrillo I, Guerra-Castillo FX, Pompa-Mera EN, et al. Prevalence of gene rearrangements in Mexican children with acute lymphoblastic leukemia: A population study-report from the Mexican Interinstitutional Group for the identification of the causes of childhood leukemia. Biomed Res Int 2014;2014:210560.  Back to cited text no. 23
    
24.
Jiménez-Morales S, Miranda-Peralta E, Saldaña-Alvarez Y, Perez-Vera P, Paredes-Aguilera R, Rivera-Luna R, et al. BCR-ABL, ETV6-RUNX1 and E2A-PBX1: Prevalence of the most common acute lymphoblastic leukemia fusion genes in Mexican patients. Leuk Res 2008;32:1518-22.  Back to cited text no. 24
    
25.
Tirado CA, Shabsovich D, Yeh L, Pullarkat ST, Yang L, Kallen M, et al. A (1;19) translocation involving TCF3-PBX1 fusion within the context of a hyperdiploid karyotype in adult B-ALL: A case report and review of the literature. Biomark Res 2015;3:4.  Back to cited text no. 25
    
26.
Deininger MW, Goldman JM, Melo JV. The molecular biology of chronic myeloid leukemia. Blood 2000;96:3343-56.  Back to cited text no. 26
    
27.
Kaeda J, O'shea D, Szydlo RM, Olavarria E, Dazzi F, Marin D, et al. Serial measurement of BCR-ABL transcripts in the peripheral blood aftet allogeneic stem cell transplantation for chronic myeloid leukemia: An attempt to define patients who may not require further therapy. Blood 2006;107:4171-6.  Back to cited text no. 27
    
28.
Garg R, Kantarjian H, Thomas D, Faderl S, Ravandi F, Lovshe D, et al. Adults with acute lymphoblastic leukemia and translocation (1;19) abnormality have a favorable outcome with hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with methotrexate and high-dose cytarabine chemotherapy. Cancer 2009;115:2147-54.  Back to cited text no. 28
    
29.
Leoni V, Biondi A. Tyrosine kinase inhibitors in BCR-ABL positive acute lymphoblastic leukemia. Haematologica 2015;100:295-9.  Back to cited text no. 29
    
30.
Inaba H, Greaves M, Mullighan CG. Acute lymphoblastic leukaemia. Lancet 2013;381:1943-55.  Back to cited text no. 30
    
31.
Pallisgaard N, Hokland P, Riishøj DC, Pedersen B, Jørgensen P. Multiplex reverse transcription-polymerase chain reaction for simultaneous screening of 29 translocations and chromosomal aberrations in acute leukemia. Blood 1998;92:574-88.  Back to cited text no. 31
    
32.
Jamil A, Theil KS, Kahwash S, Ruymann FB, Klopfenstein KJ. TEL/AML-1 fusion gene. its frequency and prognostic significance in childhood acute lymphoblastic leukemia. Cancer Genet Cytogenet 2000;122:73-8.  Back to cited text no. 32
    
33.
Greaves MF, Wiemels J. Origins of chromosome translocations in childhood leukaemia. Nat Rev Cancer 2003;3:639-49.  Back to cited text no. 33
    
34.
Moorman AV, Ensor HM, Richards SM, Chilton L, Schwab C, Kinsey SE, et al. Prognostic effect of chromosomal abnormalities in childhood B-cell precursor acute lymphoblastic leukaemia: Results from the UK Medical Research Council ALL97/99 randomised trial. Lancet Oncol 2010;11:429-38.  Back to cited text no. 34
    


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