Friday Aug 04, 2023

#248 Ornithine Transcarbamylase (OTC) Deficiency

In this episode we are learning about Ornithine transcarbamylase (OTC) deficiency, an X-linked genetic disorder that prevents the breakdown and excretion of ammonia. 

When ammonia builds up in the body, it can rise to toxic levels where it affects the central nervous system. This allows ammonia to accumulate in the bloodstream, rising to toxic levels where it affects the central nervous system. OTC is the most common of the urea cycle disorders.

We are joined by three OTC experts with professional and lived experience! Dr. Aimée Dudley is a Senior Investigator at the Pacific Northwest Research Institute (PNRI). Her laboratory performs genetic research that is used to aid variant interpretation. Dr. Andrea Gropman is the Principle Investigator of the Urea Cycle Rare Disease Consortium (UCDC) and the Division Chief of Neurodevelopmental Pediatrics and Neurogenetics at Children’s National Hospital. Tresa Warner provides her personal experience and shares her insight as the mother of a child with OTC deficiency. She also serves as the president of the National Urea Cycle Disorders Foundation. 


Aimée Dudley, PhD, is a Senior Investigator and the Director of Educational Outreach at PNRI. She earned her BS in biochemistry and molecular biology from the University of Massachusetts at Amherst and her PhD in genetics from Harvard Medical School. Dr. Dudley was an Alexander Hollaender Distinguished Postdoctoral Fellow in Dr. George Church’s laboratory at Harvard Medical School. In addition to her roles at PNRI, Dr. Dudley is a scientific advisor to FenoLogica Biosciences, a scientific instrumentation company founded based on technology developed in her lab. She serves as an Associate Editor at PLoS Genetics. Dr. Dudley also co-chairs the Washington Research Foundation’s Postdoctoral Fellowship Selection Committee. As PNRI’s Director of Educational Outreach, she partners with community groups to bring high school and undergraduate students from underrepresented communities to PNRI to explore science as a career. She also mentors graduate students through her affiliate appointment in the University of Washington’s Department of Genome Sciences, and as a faculty member in the Molecular Engineering Graduate Program and the Molecular and Cellular Biology Graduate Program.


Andrea Gropman, M.D., FAAP, FACMG, FANA, is Chief of Neurogenetics and Neurodevelopmental Pediatrics at Children’s National Hospital and a Professor of Pediatrics, Neurology, Genomics and Personalized Medicine at George Washington University. Dr. Gropman is the Principal Investigator of the Urea Cycle Disorders Consortium (UCDC) and serves leadership roles on the Rare Disease Clinical Research Network and in genetic, metabolic and neurology societies. She has published over 200 articles and reviews and contributed chapters to classic textbooks in genetics and neurology. Dr. Gropman is one of the associate editors of the classic textbook, Swaiman’s Pediatric Neurology and co-author of the textbook, X & Y Chromosomal Variations. She received her M.D. from the University of Massachusetts School of Medicine, completed a residency in Pediatrics at Johns Hopkins Hospital in Baltimore, MD and subsequent fellowships in neurology/child neurology at George Washington University and Children’s National, Washington, D.C., clinical and biochemical genetics at the National Institutes of Health, and a mini fellowship in neuroimaging and magnetic resonance spectroscopy at the Huntington Medical Research Institute in Pasadena, CA. She is board certified in neurology/child neurology, genetics, biochemical genetics and neurodevelopmental disabilities.


Tresa Warner is a parent of a child living with OTC and the President of the Board of Directors of the National Urea Cycle Disorders Foundation, a non-profit organization dedicated to the identification, treatment, and cure of urea cycle disorders. The foundation was formed in 1988 by a handful of parents whose children were affected by urea cycle disorders and has since become a nationally recognized resource of information and education for families and healthcare professionals.

On This Episode We Discuss:

  • Urea Cycle disorders, commonalities and symptoms
  • OTC deficiency overview
  • Diagnosis and treatment of OTC deficiency
  • OTC deficiency and newborn screening panels
  • Variants of uncertain significance in the OTC gene
  • New potential treatments and cures of OTC deficiency
  • Challenges faced by people with OTC deficiency and their families and actions that people with OTC deficiency and their families can do to cope with the challenges of the disease
  • The role of the Urea Cycle Rare Disease Consortium in research and the National Urea Cycle Disorders Foundation in supporting people and families with OTC deficiency


Links we mention in the episode:

Article: The functional impact of 1,570 individual amino acid substitutions in human OTC

Press release: Novel Genetic Screening Tool Offers Hope for Babies Born With Life-Threatening Metabolic Disorder

Website: The Dudley Lab

Website: Urea Cycle Disorders Consortium

Website: National Urea Cycle Disorders Foundation

Stay tuned for the next new episode of DNA Today on August 11th, 2023 where we’ll be joined by Dan Riconda and John Zimmerman to discuss men in genetic counseling in the third installment of our GC history series! New episodes are released every Friday. In the meantime, you can binge over 245 other episodes on Apple Podcasts, Spotify, streaming on the website, or any other podcast player by searching, “DNA Today”. Episodes since 2021 are also recorded with video which you can watch on our YouTube channel.  


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