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Marshall Summar, MD

Director, Rare Disease Institute | Division Chief, Genetics and Metabolism
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  • Main Hospital Washington, District of Columbia 20010 1-888-884-BEAR (2327)

Languages Spoken

  • English


Board Certifications

  • American Board of Med. Genetics/Clinical Genetics
  • American Brd of Med Genetics/Clin Biochemical Gen

National Provider ID: 1336231745

This faculty member (or a member of their immediate family) has a working relationship (i.e. consulting, research, and/or educational services) with the companies listed below. These relations have been reported to the health system leadership and, when appropriate, management plans are in place to address potential conflicts.

Outside Interests

  • Asklepion Pharmaceuticals



Dr. Summar is well-known for his pioneering work in caring for children diagnosed with rare diseases. He joined Children’s National in 2010 from Vanderbilt University. At Children’s National he leads the Division of Genetics and Metabolism, currently the largest clinical division in the world seeing over 8500 patients a year with rare diseases. Dr. Summar’s laboratory works on both devices and treatments for patients with genetic diseases and adapting knowledge from rare diseases to mainstream medicine. His work has resulted in new drugs in FDA trials for patients with congenital heart disease and premature birth. He has over 30 patents and patent applications. His laboratory is best known for its work in the rare diseases affecting nitrogen and ammonia metabolism. 

Dr. Summar has also organized and led a large number of international work groups to develop standards of care and treatment for rare diseases resulting in significant improvements in outcomes. Dr. Summar developed a program with NIH where very young children can benefit from NIH research programs at Children’s National. Dr. Summar is board-certified in Pediatrics, Clinical Genetics, and Biochemical Genetics and has been listed with Best Doctor’s in America since 2004. He serves on the board of directors of the National Organization for Rare Disorders (Chairman) and the Society of Inherited Metabolic Diseases (President). He directs the National Organization for Rare Diseases Scientific and Medical Advisory Committee and is spearheading an effort to develop national standards for families to collect information about poorly understood rare diseases affecting 25 million Americans. Dr. Summar also holds the Margaret O'Malley Professorship in Genetic Medicine. He is very active in newborn screening issues developing testing and follow-up systems.

Education & Training

Education & Training

  • Fellowship Program, Genetics, 1990
    Vanderbilt University
  • Residency Program, Pediatrics, 1988
    Vanderbilt University
  • Internship Program, Pediatrics, 1986
    Vanderbilt University
  • MD, 1985
    University of Tennessee College of Medicine
  • BS, 1981
    Vanderbilt University


Horizon Pharma gift establishes first clinical team endowment at Children’s National Rare Disease Institute

Children’s National Health System and Horizon Pharma plc are pleased to announce the creation of the Horizon Pharma Clinical Care Endowment, the first clinical team endowment at the Children’s National Rare Disease Institute. The endowment is made possible by a generous $3 million commitment over six years from Horizon Pharma USA, Inc., a wholly owned subsidiary of Horizon Pharma plc – a biopharmaceutical company dedicated to improving the lives of people living with rare diseases.  

Children's National Health System to Collaborate with the Regeneron Genetics Center in a Large-Scale Whole Exome Sequencing Research Study of Undiagnosed Diseases

Children's announces the launch of a major three-year research study of undiagnosed diseases in partnership with the Regeneron Genetics Center (RGC, a subsidiary of Regeneron Pharmaceuticals, Inc.). The RGC will conduct whole exome sequencing, which looks at all the protein-coding DNA in a genome, for patients in the study.

Research & Publications

Research & Publications

Assessing the functional characteristics of synonymous and nonsynonymous mutation candidates by use of large DNA constructs

(2007) Am.J.Hum.Genet

Current strategies for the management of neonatal urea cycle disorders

(2001) J.Pediatr

Diagnosis symptoms frequency and mortality of 260 patients with urea cycle disorders from a 21year multicentre study of acute hyperammonaemic episodes

(2008) Acta Paediatr

DLCitrulline ameliorates chronic hypoxiainduced pulmonary hypertension in newborn piglets

(2009) Am.J.Physiol Lung Cell Mol.Physiol

Genetic continuity after the collapse of the Wari empire Mitochondrial DNA profiles from Wari and postWari populations in the ancient Andes

(2009) Am.J.Phys.Anthropo

Genetic variation in the urea cycle a model resource for investigating key candidate genes for common diseases

(2009) Hum.Mutat

Neonatal pulmonary hypertensionureacycle intermediates nitric oxide production and carbamoylphosphate synthetase function

(2001) N.Engl.J.Med

Nitric oxide precursors and congenital heart surgery a randomized controlled trial of oral citrulline

(2006) J.Thorac.Cardiovasc.Surg

Pharmacokinetics and safety of intravenously administered citrulline in children undergoing congenital heart surgery potential therapy for postoperative pulmonary hypertension

(2007) J.Thorac.Cardiovasc.Surg

View publications on PubMed

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