Very Long Chain Acyl Coa Dehydrogenase Deficiency: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Very Long Chain Acyl Coa Dehydrogenase Deficiency?
A primary care doctor often helps manage day to day care. Most people also see a metabolic specialist, and sometimes a cardiologist for the heart. A dietitian can help with the eating plan, and care works best when these doctors work together.
What it is
Very long chain acyl CoA dehydrogenase deficiency, often called VLCAD deficiency, is a rare inherited condition affecting an enzyme that helps the body turn fat into energy. People with this condition cannot break down certain fats called very long chain fatty acids. When the body needs fat for fuel, such as during fasting, it struggles to make energy, causing low blood sugar and a buildup of harmful substances.
Symptoms
Symptoms vary from person to person. Common signs include low blood sugar, extreme sleepiness, vomiting, and poor feeding in babies. Muscle pain, weakness, and cramping can happen, especially after exercise or fasting. In serious cases, the heart muscle can weaken.
Causes and who gets it
VLCAD deficiency is caused by changes in a gene called ACADVL and is inherited in an autosomal recessive way, meaning a child must get one changed gene from each parent. It is rare, affecting roughly 1 in 40,000 to 120,000 babies.
How doctors diagnose it
Most cases are found through newborn screening, which uses a small blood sample from a heel prick. If the screening is abnormal, doctors confirm it with blood tests and genetic testing.
Treatment
There is no cure, but treatment can prevent serious problems. The main approach is avoiding long periods without food and eating frequent meals that are low in fat and higher in carbohydrates. Doctors may prescribe medium chain triglyceride oil as an alternate fuel source.
When to see a doctor
See a doctor right away for vomiting, extreme sleepiness, confusion, or very low energy, especially during an illness or after missing meals. Signs of heart trouble, like chest pain or fainting, need urgent attention.
How a direct primary care or concierge doctor fits in
A direct primary care doctor, where the patient pays a flat monthly fee instead of using insurance, or a concierge doctor, can be a helpful partner. These doctors often offer longer appointments and easier access. They can handle routine care, order follow up tests, and guide families during sick days, referring to specialists when needed.
Common questions
Does VLCAD deficiency go away as a person gets older?
No, the gene change is present for life. Symptoms may be milder with age, but the condition does not disappear, and ongoing care usually remains important.
Why is it important not to go too long without eating?
When a person does not eat for a long time, the body burns fat for energy. People with VLCAD deficiency cannot break down certain fats properly, so fasting can cause low blood sugar and serious illness. Frequent meals help prevent this.
Can someone with VLCAD deficiency exercise?
Many people can be active, but long, hard exercise without enough fuel can trigger muscle pain. A doctor or dietitian can help plan safe activity and snacks.
How is VLCAD deficiency found in newborn babies?
Most babies in the United States get a heel prick blood test in the first days of life. This screening can flag VLCAD deficiency before symptoms start, letting families begin care right away.
Sources
- NIH Genetic and Rare Diseases Information Center - Very long chain acyl-CoA dehydrogenase deficiency
- MedlinePlus Genetics - Very long-chain acyl-CoA dehydrogenase deficiency
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
