What are Long-Chain Fatty Acid Oxidation Disorders?

Long-chain fatty acid oxidation disorders (FAOD) are a group of autosomal recessive conditions that prevent the body from breaking down long-chain fatty acids into energy.

Beginning from early in life to as late as teenage or adulthood, patients with FAOD present with acute crises of energy metabolism and severe energy deficiency. This can lead to potentially severe complications: 

  • Rhabdomyolysis (breakdown of muscle fibers into the blood)
  • Low blood sugar (hypoglycemia)
  • Decreased muscle tone (hypotonia) and weakness
  • Heart muscle weakness (cardiomyopathy)

Several thousand people in the US have long-chain FAODs, which include six genetic conditions where a certain enzyme is missing or not working correctly. The most common four are:

  • 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

 Early diagnosis is possible, as newborns are now screened for FAOD in the US.



There are currently no approved drugs or treatments specifically for LC-FAOD. Some people are able to manage their health by avoiding fasting, following a low fat diet, using a medium-length, even-chain triglyceride (MCT) oil and/or taking prescribed carnitine.

UX007, a highly purified form of a synthetic seven carbon fatty acid triglyceride compound, is an investigational product that is being studied for the treatment of LC-FAOD. It is intended to provide people with LC-FAOD with medium-length, odd-chain fatty acids that are metabolized to bypass faulty pathways and provide an alternative energy source.


Save Babies


The Metabolic Foundation

The Fatty Oxidation Disorders (FOD) Family Support Group

Mito Action

If you are a member of an FAOD patient organization and would like to be listed here, please contact us.


For more information on the Phase 2 clinical study, please visit the study page.

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