John J. Mitchell, MD, M.Sc., FRCP, Pediatric Endocrinologist

Pediatric Endocrinology and Biochemical Genetics
Fun fact about me 

I like to skateboard.

I love working with children and their families because 
I enjoy working with families with chronic disease as I get to know the families and work with them through tough times. I find that these children have amazing resilience and courage and I often am in awe of how well they cope.

Hospital information

Academic appointments 

Associate Professor of Human Genetics and Pediatrics, McGill University

Other appointments 

MUHC Association of Clinical Researchers, Member of the executive committee



1984-1988 B.Sc. (Biological psychology), University of British Columbia

Medical Degree 

1994-1998 Doctor of Medicine, University of British Columbia


1998-2001 Pediatric residency,  Montreal Children’s Hospital-McGill University


2001-2003 Clinical Fellow - Pediatric Endocrinology,  Montreal Children’s Hospital-McGill University

2003-2004 Clinical Fellow – Biochemical Genetics  Children’s Hospital at Westmead-Sydney University, Australia


Research interests 

I am interested in the treatment of rare metabolic diseases known as orphan diseases.  Diseases such as phenylketonuria (PKU) or lysosomal storage disorders are caused by a lack of a specific enzyme.  Patients  missing that enzyme will not be able to break down certain sugars or proteins.  The accumulation of these substances can cause damage to one organ (as phenylalanine does to the brain in PKU), or to many organs (in the way that glycosaminoglycans affect lungs, bones, eyes and heart in Morquio syndrome).  My research aims to prevent organ damage by replacing the missing enzyme or by using alternate routes to prevent accumulation of the toxic substances.  I am also interested in how the Canadian and Quebec government evaluate and  decide on approval and coverage of orphan therapies.

Research foci 
  • Phenylketonuria
  • Morquio syndrome
  • Farber disease
  • Lysosomal storage diseases
  • Glycogen storage disease
  • Orphan diseases

PKU; Morquio syndrome; orphan disease; orphan therapy

Selected publications 

Rousseau-Nepton I*, Laforte D, Mok E, Fenyves D, Huot C, Constantin E, Mitchell J. Quality of sleep and quality of life of patients with glycogen storage disease on standard and modified uncooked cornstarch, Journal of Inherited Metabolic Disease, submitted for publication.

Burton BK, Berger KI, Lewis GD, Tarnopolsky M, Treadwell M, Mitchell JJ, Muschol N, Jones SA, Sutton R, Pastores GM, Lau H, Sparkes H, Genter F, Shaywitz AJ, Harmatz P. Safety and Physiological Effects of Two Different Doses of Elosulfase Alfa in Patients With Morquio A Syndrome: a Randomized, Double-blind, Pilot study, American Journal of Medical Genetics: Part A, published online June 2015.

Khangura SD, Karaceper MD, Trakadis Y, Mitchell JJ, Chakraborty P, Tingley K, Coyle D, Grosse S, Kronick JB, Laberge AM, Little J, Prasad C, Sikora L, Siriwardena K, Sparkes R, Speechley KN, Stockler S, Wilson B, Wilson K, Zayed R and Potter BK Scoping review of patient- and family-oriented outcomes and measures for chronic pediatric disease.  BMC Pediatrics, 7, 2015

Rousseau-Nepton I*, Okubo M, Grabs R, FORGE Canada Consortium, Mitchell J, Polychronakos C, Rodd C. Whole exome sequencing identifies a founder AGL mutation in Inuit from Nunavik with Glycogen Storage Disease type IIIa, Canadian Medical Association Journal, published Online January 19, 2015.

Clarke, LA, Maranda B, Mitchell, JJ, Raiman JAJ, Rockman-Greenberg C, Sirrs S,  Sparkes R, and Stockler S, Canadian Expert Opinion: Recommendations for the use of elosulfase alfa in the management of Morquio A Syndrome (MPS IVA)., published on Garrod Association Website,, 2014

Camp KM, Parisi MA, Acosta PA, Berry G, Bilder DA,  Blau N ,. Bodamer O, Brosco JP, Brown CSI, Burlina A, Burton BK, Chang CS , Coates PM, Cunningham  AC, Dobrowolski  SF, Ferguson JH, Franklin T, Frazier DM , Grange DK, Carol L. Greene , Groft SC, Harding CO, Howell RR, Huntington KL , Hyatt-Knorr HD,  Jevaji IP, Levy HL , Lichter-Konecki  U,  Lindegren ML, Lloyd-Puryear MA, Matalon K, MacDonald  A, McPheeters ML, Mitchell JJ, Mofidi  S, Moseley KD, Mueller CM, Mulberg  AE, Nerurker LA, Ogata BN, Pariser AR, Prasad S, Pridjian G, Rasmussen SA, Reddy UM, Rohr FJ , Singh R, Sirrs SM, Stremer SE,. Tagle DA, Thompson SM, Urv TK, Utz JR , van Spronsen F, Vockley J, Waisbren S , Weglick LS, White DA, Whitley CB, Wilfond BS,  Yannicelli S, Young JM   Phenylketonuria Scientific Review Conference: State of the Science and Future Research Needs, Molecular Genetics and Metabolism, 112 (2):87-102, 2014.


Vockley J, Andersson HC, Kevin M. Antshel KM, Braverman NE, Burton BK, Frazier DM, Mitchell J, Smith WE, Thompson BHand Berry SA; For the American College of Medical Genetics and Genomics Therapeutic Committee, Phenylalanine Hydroxylase Deficiency Diagnosis and Management Guideline, Genetics in Medicine, 16 (2):188-200, 2014.