Walter Kahr

Senior Scientist
Cell Biology

Dr. Kahr received his MD and PhD (Biochemistry) from the University of Toronto in 1994. After post-graduate training in Internal Medicine (University of Toronto), Hematology (McMaster University), and a postdoctoral fellowship in the Department of Pathology and Molecular Medicine (McMaster University), he joined the Division of Haematology/Oncology at SickKids in 2003 as a Clinician-Scientist. He is currently a Senior Scientist in the Cell Biology Program of the Research Institute with a research laboratory at SickKids Research Institute. His main clinical and research interests are haemostasis and thrombosis, with a focus on the role of platelets in health and disease.

Research

Dr. Kahr's research is aimed at understanding the development and function of platelets, tiny blood cells that initiate and co-ordinate clotting at wounds. Platelets do this by adhering, aggregating and secreting a wide assortment of molecules, which helps normal clotting and can also contribute to thrombi that cause heart attacks and strokes. Many of his insights into the mechanisms of platelet development and function have come from studies of patients with inherited disorders. His particular interest is alpha granules, which platelets use to transport and secrete several hundred different proteins. His team has identified several proteins and cellular pathways involved in the development of alpha granules in the cells that produce platelets, the bone marrow megakaryocytes.

Education and experience

• 1994: PhD, Department of Biochemistry, University of Toronto
• 1994: MD, Department of Medicine, University of Toronto
• 1994–1997: Internal Medicine, Department of Medicine, University of Toronto
• 1997–1999: Hematology, Department of Medicine, McMaster University
• 1999–2002: Postdoctoral Research Fellowship, Department of Pathology and Molecular Medicine, McMaster University
• 2003–Present: Staff Physician, Division of Haematology/Oncology, The Hospital for Sick Children
• 2007–Present: Associate Member, Institute of Medical Sciences, School of Graduate Studies, University of Toronto
• 2014–Present: Senior Scientist, Cell Biology Program, Research Institute, The Hospital for Sick Children
• 2018–Present: Professor, Department of Paediatrics, University of Toronto
• 2018–Present: Professor, Department of Biochemistry, University of Toronto

Achievements

• 2018: Inaugural Janet Rossant Research Innovation Prize. Leader of the team recognized for interdisciplinary research arising from work conducted at SickKids.
• 2018–Present: Executive Committee Member, National Institutes of Health, ClinGen Rare Gene Variant Curation Group, Hemostasis/Thrombosis Clinical Domain Working Group and Platelet Function Disorder Subgroup, University of North Carolina at Chapel Hill, USA.

1. Mutations in NBEAL2, encoding a BEACH protein, cause gray platelet syndrome. Nature Genetics 43:738–740 (2011)
2. Germline mutations in ETV6 are associated with thrombocytopenia, red cell macrocytosis and predisposition to lymphoblastic leukemia. Nature Genetics 47:535–538 (2015)
3. Requirement of VPS33B, a member of the Sec1/Munc18 protein family, in megakaryocyte and platelet α-granule biogenesis. Blood 106: 4159–4166 (2005)
4. Abnormal megakaryocyte development and platelet function in Nbeal2−/− mice. Blood 122:3349–3358 (2013)
5. Loss of the Arp2/3 complex component ARPC1B causes platelet abnormalities and predisposes to inflammatory disease. Nature Communications 8, Article number: 14816 (2017)

See a full list of Walter Kahr's publications

Funding

• Canadian Institutes of Health Research (CIHR) Operating grants PJT153168 and PJT-156095.