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Johann Hitzler

Title: Senior Scientist, Developmental & Stem Cell Biology
Designations: MD, FRCP(C), FAAP
Phone: 416-813-8887
Alternate Contact Name: Celeste Alora
Alternate Phone: 416-813-6382 ext. 308810
Alternate Email:


Dr. Hitzler completed his paediatric residency and fellowship in paediatric haematology/oncology at The Hospital for Sick Children.  He obtained post-doctoral research training at the Ontario Cancer Institute in Toronto and at St. Jude Children's Research Hospital in Memphis, TN. He is a staff physician in the Division of Haematology/Oncology at Sickkids and a Senior Scientist in the Developmental & Stem Cell Biology Program at The Hospital for Sick Children Research Institute. 


Acute myeloid leukemia (AML) in children with Down syndrome develops with 150-fold higher frequency and often is preceded by a pre-leukemic, but spontaneously healing, disorder during the newborn period called transient leukemia.

Dr. Hitzler’s laboratory research is focused on the genomic and functional analysis of leukemia cells to determine how this progression from neonatal pre-leukemia to fully transformed leukemia takes place and to find a way to predict which children are at highest risk. His clinical research aims i) to determine the optimal treatment for children with myeloid leukemia of Down syndrome in a large clinical trial conducted by the Children’s Oncology Group (COG), ii) to find out why children with Down syndrome and acute lymphoblastic leukemia (ALL) more often experience life-threatening infections during treatment and how to prevent them, and iii) how to innovate leukemia treatment for this vulnerable group of children.   

Education and experience

  • 2012–Present: Head, Section Leukemia Lymphoma in the Division of Hematology/Oncology, SickKids Research Institute, Toronto, ON
  • 2012–Present: Senior Scientist, Developmental and Stem Cell Biology, SickKids Research Institute, Toronto, ON  
  • 2009–Present: Associate Member, Institute of Medical Science, University of Toronto, Toronto, ON
  • 1998–Present: Physician, Division of Haematology/Oncology, The Hospital for Sick Children , Toronto, ON 


  • 2017–Present: Co-Chair, Down syndrome Task    Force, Therapeutic Advances in Childhood Leukemia Consortium (TACL)  
  • 2015–Present:  Co-chair, study AAML1531, Risk stratified Therapy for Acute Myeloid Leukemia in Down Syndrome, Children’s Oncology Group (COG) 
  • 2015: Chair, Down Syndrome ALL Task Force, Children’s Oncology Group 
  • 2013–Present: Member, AML Steering Committee, Children’s Oncology Group  
  • 2012 & 2008: Teaching Award: The Hospital for Sick Children, Division of Haematology/Oncology 
  • 2009: Schwartz-Reisman Visiting SickKids Scholar Award 
  • 2007: Ontario Researcher of the Month, Canadian Cancer Society 


  1. Rabin K, Izraeli S, Hijiya N, Hitzler J: Need for new thinking:  Treatment of relapsed leukemia in children with Down syndrome. Commentary, Pediatric Blood and Cancer Jan 2019 DOI 10.1002/pbc.27644 
  2. F Meyr, G Escherich, G Mann, T Klingebiel, A Kulozik, C Rossig, M Schrappe, G Henze, A von Stackelberg, J Hitzler: Outcomes of treatment for relapsed acute lymphoblastic leukaemia in children with Down syndrome, (Br J Haematol. 2013 Jul;162(1):98-106 
  3. Johann K. Hitzler, Wensheng He, John Doyle, Mitchell Cairo, Bruce M. Camitta, Ka Wah Chan, Miguel A. Diaz Perez, Christopher Fraser, Thomas G. Gross, John  T. Horan, Alana A. Kennedy-Nasser, Carrie Kitko, Joanne Kurtzberg, Leslie Lehmann, Tracey O’Brien, Michael A. Pulsipher, Franklin O. Smith, Mei-Jie Zhang, Mary Eapen, Paul A. Carpenter: Outcome of Transplantation for Acute Myelogenous Leukemia in Children with Down Syndrome (Biol Blood Marrow Transplant. 2013 Jun;19(6):893-7     
  4. Chen J, Li Y, Doedens M, Wang P, Shago M, Dick J, Hitzler J. (2010) Functional differences between myeloid leukemia–initiating and transient leukemia cells in Down syndrome. Leukemia.  24(5):1012-7   
  5. Ma Z, Morris SW, Valentine V, Li M, Herbrick JA, Cui X, Bouman D, Li Y, Mehta PK, Nizetic D, Kaneko Y, Chan GC, Chan LC, Squire J, Scherer, Hitzler JK: Fusion of two novel genes, RBM15 and MKL1, in the t(1;22) (p13;q13) of acute megakaryoblastic leukemia.  Nature Genetics 2001: 28: pp 220-221. 

See a full list of Johann Hitzler's publications.

  • Canadian Cancer Society Research Institute (CCSRI) 
  • Canadian Institute of Health Research (CIHR) 
  • National Institutes of Health (NIH) 
  • Ontario Ministry of Health Drug Innovation Fund 
  • Canadian Cancer Society, Ontario Division 
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