Long Chain 3 Hydroxyacyl 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 Long Chain 3 Hydroxyacyl Coa Dehydrogenase Deficiency?
A pediatrician or family doctor often manages day-to-day care and coordinates the team, which usually includes a metabolic specialist and a dietitian. Eye, heart, and nerve doctors may join if those organs are affected. A direct primary care doctor charges a flat monthly fee instead of billing insurance; a concierge doctor usually charges more and often works alongside insurance. Either can handle routine monitoring and refer to specialists.
What it is
Long chain 3 hydroxyacyl CoA dehydrogenase deficiency, often called LCHAD deficiency, is a rare inherited condition that affects how the body turns fat into energy. People with this condition lack enough of a working enzyme. When the body cannot break down long chain fatty acids, they build up and can harm the liver, muscles, heart, and eyes. Problems appear most during fasting, illness, or hard exercise, and low blood sugar can develop.
Symptoms
Symptoms often start in infancy and can include low blood sugar, extreme sleepiness, vomiting, and poor feeding. Without treatment, the condition can cause liver problems, muscle weakness, heart trouble, vision loss over time, and nerve damage.
Causes and who gets it
LCHAD deficiency is inherited, meaning a child must get a changed copy of the gene, called HADHA, from both parents. Parents are usually just carriers with no symptoms. It affects roughly 1 in 50,000 to 100,000 babies, and newborn screening finds many cases early.
How doctors diagnose it
Many babies are diagnosed through newborn screening, which uses a small blood sample from the heel. Doctors confirm it with blood and urine tests and genetic testing of the HADHA gene. Testing may also follow unexplained low blood sugar, liver problems, or muscle symptoms.
Treatment
Treatment focuses on avoiding fasting and following a special diet low in fat, planned with a dietitian. People eat frequent meals with extra carbohydrates, and some take medium chain triglyceride oil. Doctors may prescribe essential fatty acids such as DHA, and they monitor the heart, eyes, muscles, and liver over time.
When to see a doctor
Anyone with this condition should see a doctor promptly during illness, vomiting, poor eating, unusual sleepiness, or confusion, which can signal a metabolic crisis. Seek emergency care for seizures, extreme drowsiness, or trouble waking. Regular checkups matter too, since eye, nerve, heart, and muscle problems can develop slowly.
Common questions
Can a person with LCHAD deficiency live a normal life?
Many people do well when the condition is found early and diet and fasting rules are followed closely. Severity varies, and some have lasting problems with muscles, nerves, vision, or the heart.
Why is fasting so dangerous with this condition?
When food runs out, a healthy body burns stored fat for energy. A person with LCHAD deficiency cannot complete that process, so blood sugar can drop and harmful fats build up.
Can adults have LCHAD deficiency without knowing it?
Most cases are found in infancy or childhood, especially with newborn screening. Rarely, milder forms are found later after unexplained muscle or liver problems.
Should parents of a child with LCHAD deficiency be tested?
Parents are usually carriers with no symptoms, but testing can confirm it and helps families understand the chance of the condition in future pregnancies. A genetic counselor can explain the options.
Sources
- MedlinePlus Genetics - Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency
- NIH Genetic and Rare Diseases Information Center - Long chain 3-hydroxyacyl-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.
