Clinical and Laboratory ObservationsMethylenetetrahydrofolate Reductase and Glutathione S-Tranferase Gene Polymorphisms in Secondary Mixed Phenotype Acute Leukemia: A Case ReportSkoric, Dejan MD, PhD; Ivana, Joksic MD, PhD; Tanja, Radic MSc; Jovana, Jakovljevic BSc; Petar, Ivanovski MD, PhD; Tatjana, Simic MD, PhDAuthor Information *Department of Hematology and Oncology, University Children’s Hospital †Clinic of Gynecology and Obstetrics “Narodni front” ‡Institute of Medical and Clinical Biochemistry §Institute of Medical Physiology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia This work was granted by the Project 175052 financed by Ministry of Education, Science and Technological Development of Republic of Serbia. The authors declare no conflict of interest. Reprints: Joksic Ivana, MD, PhD, Clinic of Gynecology and Obstetrics “Narodni front”, Kraljice Natalije St 62, Belgrade 11000, Serbia (e-mail: firstname.lastname@example.org). Received February 10, 2013 Accepted September 11, 2013 Journal of Pediatric Hematology/Oncology: April 2014 - Volume 36 - Issue 3 - p e152–e154 doi: 10.1097/MPH.0000000000000050 Buy Metrics Abstract Background: Therapy-induced leukemia is a well-known clinical syndrome occurring as a late complication in patients treated with cytotoxic therapy. Observation: We herein present results of analysis of common gene polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and glutathione S-transferase (GST) genes in a 10-year-old boy who developed very rare type of cancer, mixed phenotype acute leukemia, 6 years after treatment of acute lymphoblastic leukemia. Conclusions: Impairment in function of GST and MTHFR enzymes found in our patient may have contributed to the development of secondary mixed phenotype acute leukemia, although precise mechanism remains elusive. Copyright © 2014 Wolters Kluwer Health, Inc. All rights reserved.