Also known as Carnitine palmitoyltransferase (CPT I or CPT II) deficiency, very long chain acyl-CoA dehydrogenase (VLCAD) deficiency, long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) deficiency, trifunctional protein (TFP) deficiency
What is it?
Long-chain fatty acid oxidation disorders (LC-FAOD) are a group of rare conditions that impair the body’s metabolism from breaking down certain fats from food into energy.
What Causes It?
The body typically uses glucose (sugar) for energy, but also gets energy from fat when it uses up available glucose. People with fatty acid oxidation disorders (FAOD) cannot use fat for energy.
What Are Some Common Symptoms?1, 2
- Muscle cell rupture
- Low blood sugar
- Muscle weakness
- Decreased muscle tone
- Disease of the heart muscle
How Many People Have It?
It is estimated that 2,000 to 3,500 people are living with LC-FAOD in the U.S.2
- Vockley, J. What is Rhabdomyolusis? INFORM Network Website. Published December 20, 2019. Accessed October 31, 2021. https://informnetwork.org/2019/12/20/rhabdomyolysis-from-fatty-acid-oxidation-disorders/
- Ultragenyx Pharmaceutical Inc. Data on file. 2019.
Intended for U.S. audiences only
Participate in LC-FAOD Research
To talk to someone and get more information about Ultragenyx clinical trials and research, email [email protected].
Clinical Trials
LC-FAOD In-Clinic Disease Monitoring Program
Observational Research
Research plays a critical part in advancing science and treatments. Volunteers who participate in this research are essential. Future therapies would not be possible without them. Participating in clinical trials, interviews, observational studies, and disease monitoring programs help to drive research, treatment development, and disease education. It is also a way to advocate for yourself and your community.
Upcoming Community Events
Participate in Events Near YouMay 6
During this week the Osteogenesis Imperfecta (OI) community members educate and raise awareness on the condition. They celebrate Wishbone Day, the international Day of Awareness for OI.
May 15
Every year on May 15, the mucopolysaccharidosis (MPS) and mucolipidosis (ML) community comes together to recognize those diagnosed, think about the loved ones who have been lost, thank doctors and […]
Jun 10
The OIFE Annual General Meeting (AGM) will be held in Stockholm Sweden from June 10-11, 2023. All organizations are invited to attend and to speak at the annual general meeting, […]
LC-FAOD Patient Advocacy Groups*
*These organizations are an incomplete listing of rare disease advocacy groups and are not controlled by, endorsed by, or affiliated with Ultragenyx Pharmaceutical Inc. The list is meant for informational purposes only and is not intended to replace your healthcare professional’s medical advice. Ask your doctor or nurse any questions you may have about your disease or treatment plan. If you would like to have your group added to the list, please contact [email protected].
Rare Experiences
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LC-FAOD Community Voices
Long-chain Fatty Acid Oxidation Disorder (LC-FAOD)“We may be kilometers apart, but I’m walking the same path as you.”

Myriam and Victoria
Long-chain Fatty Acid Oxidation Disorder (LC-FAOD)“We are parents, not doctors, but we fight for our children.”