Screening of polymorphisms in the folate pathway in Turkish pediatric acute lymphoblastic leukemia patients

Background and aim: Folate metabolic pathway plays a significant role in leukemogenesis because of its necessity for nucleotide synthesis and DNA methylation. Folate deficiency causes DNA damage. Thus polymorphisms of folate-related genes may affect the susceptibility to childhood Acute Lymphoblastic Leukemia [ALL]. MTHFR [Methylenetetrahydrofolate Reductase], DHFR [Dihydrofolate reductase], CBS [Cystathionine ?-synthase] and TYMS [Thymidylate Synthase] have an important role in folate pathway because their activated variants modulate synthesis of DNA and levels of folate. In this study, we aimed to investigate whether polymorphisms in genes related to folate metabolic pathway influence the risk to childhood ALL

Subject and methods: The patient groups who were diagnosed with childhood ALL at Losante Pediatric Hematology-Oncology Hospital and healthy control groups were included in the study. MTHFR 677 C-T, MTHFR 1298 A-C, CBS 844ins68, DHFR 19-bp and TYMS 1494del6 polymorphisms were screened. Genotyping of these polymorphisms was performed by Restriction Fragment Length Polymorphism [RFLP] analysis and Real Time Polymerase chain Reaction [Real Time-PCR]

Results: In total, we have screened 5 polymorphisms in the studied genes. The results were compared between childhood ALL patients and healthy groups. Genotype frequencies of MTHFR 677 C-T, MTHFR 1298 A-C, CBS 844ins68 and DHFR 19-bp del were similar for childhood ALL patients and healthy groups. However, statistical results showed that TYMS 1494del6 may be associated with ALL pathogenesis [p < 0.001]

Conclusion: We showed that TYMS polymorphism [rs2853542] may be associated with ALL pathogenesis. In addition, our results demonstrated that MTHFR, DHFR and CBS do not affect development of leukemia. Our study displays also importance as it is the first screening results to identify association with the studied polymorphisms in Turkish patients with childhood ALL and determination of the frequency in Turkish population

Detection of TET2, KRAS and CBL variants by Next Generation Sequencing and analysis of their correlation with JAK2 and FLT3 in childhood AML

Background: Acute myeloid leukemia [AML] is a heterogeneous clonal disorder in terms of cytogenetic and molecular aberrations. Ten-Eleven-Translocation 2 [TET2], Kirsten rat sarcoma viral oncogene homolog [KRAS], and Casitas B-cell lymphoma [CBL] have an important role pathogenesis of acute myeloid leukemia [AML] and their activated mutations confer proliferative and survival signals

Aim: In this study, we aimed to find possible genetic markers for molecular analysis in childhood AML by screening hot-spot exons of TET2, KRAS, and CBL using Next Generation Sequencing [NGS] analysis. In addition, association between found variants and mutations of Januse Kinase-2 [JAK2] and Fms-Related Tyrosine Kinase [FLT3] were analyzed which are important prognostic risk factors for AML

Methods: Eight patients who were diagnosed with pediatric AML at Losante Pediatric Hematology- Oncology Hospital were included to the study. Hot-spot exons of TET2, KRAS and CBL genes were screened using the NGS method. Furthermore, FLT3-Internal Tandem Duplicate [FLT3-ITD] and JAK2-V617F were analyzed by Real Time Polymerase chain Reaction [Real Time-PCR]

Results: In total, we identified 20 variants in studied genes by NGS. In our patient group, 16 variants in the TET2 [seven novel, seven missense and two silent], two variants in the KRAS [one missense and one intronic] and two variants in the CBL [two novel] were found. All of AML patients were found negative for JAK V617 F. Three of the eight patients [37.5%] showed mutations of both FLT3-ITD and TET2, KRAS, CBL

Conclusion: We found novel mutations forTET2, KRAS, and CBL. The detected variants in this article seem to be the first screening results of genes studied by NGS in childhood AML patients. Our results also showed some degree of association between FLT3-ITD and TET2, KRAS, CBL mutations

Valporic acid: is it safe to use in epileptic pediatric patient?

To evaluate the effects of a 3-month low dose valporic acid treatment [20 mg/kg/ day] on liver function tests, hematologic parameters, serum lipids and lipoprotein [a] levels in children. Twenty-one newly diagnosed epileptic pediatric patients, nine female and 12 male, aged between 18 months and 14 years old [mean age 6.3 +/- 4.3 years], were enrolled in this study, valporic acid treatment was started with a dose of 20 mg/kg/day. To evaluate the effects of valporic acid on liver function tests, hematologic parameters, and serum lipids and lipoprotein levels were measured in pre-treatment and post-treatment 3[rd] month and values in pre-treatment were compared with values in post-treatment 3[rd] month. There were no statistically significant differences between pre-treatment and post-treatment 3[rd] month values regarding liver function tests, hematologic parameters, and serum lipids [p>0.05]. But lipoprotein [a] levels in the post-treatment 3[rd] month [40.71 +/- 50.73 mg/dl] were significantly higher than the pre-treatment levels [25.86 +/- 36.54 mg/dl] [p<0.01]. It was demonstrated that low dose of valporic acid treatment did not have any significant effects on liver function tests, hematologic parameters and serum lipids after three months. On the other hand it caused an increase in lipoprotein [a] levels. We consider that although these are the initial results for lipoprotein [a] levels and further studies should be undertaken on a larger sample size to confirm our observations, epileptic pediatric patients receiving low dose of valporic acid should not be routinely checked for liver function tests, hematologic parameters and serum lipid profiles, but serum levels of lipoprotein [a] may be monitorized carefully