Marshall Summar, MD Division Chief, Genetics and Metabolism


  • Main Hospital Washington, District of Columbia 20010 1-888-884-2327

Languages Spoken

  • English


Board Certifications

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


Marshall Summar, MD, is the Chief of the Division of Genetics and Metabolism and the Margaret O’Malley Chair of Molecular Genetics. He joined Children's National Health System from Vanderbilt University School of Medicine, where he directed the Program in Translational Genetics, the DNA Core program, and started the inborn errors of metabolism program. Dr. Summar is board-certified in pediatrics, clinical genetics, and biochemical genetics.

Dr. Summar is an expert in translational studies, taking basic molecular genetics research and developing direct clinical applications. His work has piloted treatments from the rare disease field to common conditions, especially in the intensive care and emergency room setting. His work in the urea cycle has involved the development of treatment protocols, translational research, and basic molecular research into these rare defects in nitrogen metabolism. This involves clinical trials to improve the outcomes of patients with congenital heart defects, acute lung injury, asthma, and premature infants using compounds from metabolic pathways he studies.

Currently, the focus of Dr. Summar's research is the study of the interactions between common genetic variations and the environment. This work involves research in heart disease, asthma, pulmonary hypertension, oxidant injury and aging, Down syndrome, and liver disease.

Dr. Summar serves on the editorial board of The Journal of Pediatrics and is the president-elect for the Society of Inherited Metabolic Disease. He serves on the National Institutes of Health study section for the CETT program, the National Human Genetic Research Institute Fellowship Training Program Board, and the NASA radiation research review panel.

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
Patient Stories

Patient Stories: Marshall Summar

Harrison's Story

"Your child will walk, run, dance, and most likely never remember the whole ordeal. Let me assure you that it will be harder for you than your child."

Patient story

Ashley's Story

"We love going to Children's National. The first visit was very hard since we found out about the diagnosis, but after that we have only had good visits. My daughter loves going there."

Patient story

Caroline's Story

"You are probably still trying to remember how to say your child's disorder. Don't worry. It took me three days!"

Patient story

Jayden's Story

"Never lose hope. Be thankful for the time you have with your little ones, I cherish every moment that I spend with mine."

Myles's Story

"We will always be grateful for Children's National and for all the miracle workers they provide."



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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Ashley's Story

Patient story

"We love going to Children's National. The first visit was very hard since we found out about the diagnosis, but after that we have only had good visits. My daughter loves going there."

Read More of Ashley's Story

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