The Egyptian Journal of Haematology

LETTER TO THE EDITOR
Year
: 2018  |  Volume : 43  |  Issue : 3  |  Page : 149--150

Screening of EPCR gene mutations in children with acute lymphoblastic leukemia


Dilara F.A Bali1, Didem T Özkan2, Emin Kürekçi3, Nejat Akar4,  
1 Department of Medical Biology, Niğde Ömer Halisdemir University Faculty of Medicine, Niğde, Turkey
2 Vocational School of Health Service, Okan University, İstanbul, Turkey
3 LÖSANTE Children’s and Adult Hospital, Turkey
4 TOBB-ETU Hospital, Ankara, Turkey

Correspondence Address:
Dilara F.A Bali
Department of Medical Biology, Faculty of Medicine, Niğde Ömer Halisdemir University, Niğde
Turkey




How to cite this article:
Bali DF, Özkan DT, Kürekçi E, Akar N. Screening of EPCR gene mutations in children with acute lymphoblastic leukemia.Egypt J Haematol 2018;43:149-150


How to cite this URL:
Bali DF, Özkan DT, Kürekçi E, Akar N. Screening of EPCR gene mutations in children with acute lymphoblastic leukemia. Egypt J Haematol [serial online] 2018 [cited 2020 Feb 22 ];43:149-150
Available from: http://www.ehj.eg.net/text.asp?2018/43/3/149/246775


Full Text



Acute lymphoblastic leukemia, a malignant disorder of lymphoid progenitor cells, affects both children and adults, with peak prevalence between the ages of 2 and 5 years. It has been reported that the incidence of thrombosis varies between 2.4 and 11.5% in children with acute lymphoblastic leukemia [1]. Thrombosis, which is one of the major complications of acute leukemia, may cause adverse prognosis. Thromboembolic events may be caused by a variety of factors, including their own effects. It is thought to be the result of chemotherapeutic agents such as central venous line, chemotherapy, catheterization, infections, dehydration, steroid, l-asparaginase and acquired or inherited prothrombotic defects [2].

Coagulation mechanism is a complex reaction that contains negative and positive feedback reactions, multiple enzyme systems, humoral and cellular procoagulants, and anticoagulants. Membrane-bound EPCR helps increase anticoagulant protein C activation helping to prevent organ damage by thrombin-thrombomodulin complex. EPCR is expressed in dendritic cells and leukocytes, lung pneumocytes, neutrophils, heart and lungs and in the endothelial cells of the arteries [3].

The human EPCR gene is located on chromosome 20q11.2 and has four exons and three introns. To date, several polymorphisms and mutations − including a 23-bp insertion − have been reported on the human EPCR gene. Exons 2 and 3 encode most of the extracellular region of the EPCR gene [4],[5]. This insertion of 23 nucleotides preceding the insertion point (nt4031) introduces a frameshift and premature stop that deletes the entire α2 domain of the gene. The truncated protein results in absence of the cytoplasmic tail, transmembrane domain, and part of the extracellular domain. This leads to a decrease in PC activation. This has been proposed as a risk of thrombosis.

EPCR has four common haplotypes. In studies investigating whether variations in the EPCR gene or plasma sEPCR levels are risk factors for deep vein thrombosis (DVT), these A3 haplotypes have been associated with G-allele-increased plasma sEPCR levels specific for the A3 haplotype, which account for 86.5% of the variations in sEPCR levels [5].

In this study, we aimed to determine the possible EPCR gene changes, one of the factors thought to cause thrombosis in childhood leukemia, to determine the frequency of pediatric leukemia and to investigate whether these changes have any effect on thrombosis formation.

For this study, 133 children aged between 1 and 15 years who were diagnosed with acute lymphoblastic leukemia in the Hospital for Children with Leukemia were examined.

DNA samples were isolated with the MagNa Pure Automatic Isolation system (Roche Diagnostics Gmbh, Mannheim, Germany). The EPCR gene was amplified by PCR with DNA primers. 23 base insertions were screened with primers for the detection of A1 haplotypes. To detect the 23-bp insertion, the PCR product was electrophoresed in 3% agarose gel and stained with ethidium bromide and was sequenced, using a DNA sequencer (Beckman Coulter DNA Sequencer, California, ABD, USA). For the EPCR gene A-1 haplotype, DNA sequence analysis was performed on the obtained PCR products and the results were evaluated.

When the sequence was analyzed, we detected in three (2.25%) of the 133 patients screening for the EPCR genome 23-bp insertion mutation. Akar et al. reported that 23bp insertion was detected 0.8% in the healthy study population. The polymorphism (G7014C) present in the 3′UTR includes A1 haplotype changes was detected in one of 10 different patients. This change is shown in [Figure 1]. The mutation was detected in a 7-year-old male patient who was diagnosed at the age of 3 years with AML and was treated with acute myeloid leukemia (AML) BFM 2004 protocol. Acute lymphoblastic leukemia (ALL) BFM 95 h group received treatment when ALL was more dominant when the disease recurred. On recurrence, he received Nopho 88, CCG 1941, FA and clofarabine treatment protocols, but he died despite treatment.{Figure 1}

It can be predicted that the G7014C mutation in the gene 3′UTR is effective at degrading the mRNA stabilization and regulation of the EPCR gene. More research is needed to investigate the association of this change with survival. On the contrary, the frequency of 23-bp insertion at EPCR gene change in pediatric leukemia individuals was not different from the normal population.

The study is carried out in accordance with the code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving humans. This study involves blood from patients with leukemia. The Ankara University, School of Medicine Ethics Committee approved the study protocol (project No.03-107-13/2013), and informed consent was provided by the patients’ parents.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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