← All diseases

Inborn errors of metabolism

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency

An inherited disease in which the body cannot turn certain fats into energy. Blood sugar can drop during fasting and illness. Early diagnosis and avoiding fasting usually prevent problems.

Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source

Orphanet has a guideline for emergency doctors for this disease (language: French, English). See on Orphanet

Prepare an emergency card

This page is translated from the Turkish original.

This disease is followed through the “Inborn errors of metabolism” group.

Understanding the disease

This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.

What happens in this disease?

The MCAD enzyme breaks down medium-chain fatty acids. When this enzyme is missing, the body cannot turn fats into energy during fasting. Blood sugar drops. Fat waste products can build up and damage the liver and brain.

Which symptoms can occur?

Babies usually look healthy at birth. Problems appear during long periods without food or during an infection.

  • Vomiting
  • Weakness and drowsiness
  • Low blood sugar
  • Seizures, also called fits (in severe episodes)
  • Difficulty breathing (in severe episodes)
  • Liver problems

How is it diagnosed?

In many countries, babies are found through newborn screening. The blood is checked for fat waste products called acylcarnitines. The diagnosis is confirmed with a genetic test.

Treatment and care

The basis of treatment is avoiding fasting. Babies are fed often, and children are given a snack before bed. A balanced diet that is not high in fat is recommended. During illness or surgery, sugar-containing fluid into a vein may be needed. A metabolic team and a dietitian follow the child regularly. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

The disease is passed on through recessive inheritance. The mother and father are usually carriers who show no symptoms. For a couple who are both carriers, the chance of having an affected child is 1 in 4 in each pregnancy. Recessive diseases can be more common when relatives marry each other. Testing brothers and sisters as well is recommended. Genetic counselling is recommended.

Source: MedlinePlus Genetics: Medium-chain acyl-CoA dehydrogenase deficiency · GeneReviews: Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency

Key facts

How common is it?
Prevalence: 1-9 per 100 000 (Worldwide)
How is it inherited?
Autosomal recessive
When does it usually start?
Infancy, Newborn period
Gene(s) involved
ACADM

These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.

You are not alone: patient associations in Türkiye

Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.

We could not find a patient association specific to this disease.

For all rare diseases: Nadir Hastalıklar Federasyonu

Guides related to this disease

  • Special diets and medical nutrition · Metabolic diet, blood monitoring, medical formula and SGK report, sick-day plan, tube feeding and swallowing problems, school meals, supplement warning

Support and help

Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.

News about MCAD deficiency

Clinical trials (ClinicalTrials.gov)

A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.

This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.

Questions you can ask your doctor

  • Could this trial be suitable for us?
  • If we take part, how would current treatment and check-ups be affected?
  • Where does the trial take place, and how are travel and accommodation handled?
  • What happens if we want to leave the trial?

ClinicalTrials.gov lists 2 active interventional studies for this disease. 2 are recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.

Selected records (studies with a site in Türkiye first):

See all studies on ClinicalTrials.gov · Joining clinical trials

Inborn errors of metabolism: other news

Medical codes (for talking with your doctor and finding sources)

These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.

Orphanet code: ORPHA:42

No separate ICD-11 code; WHO classifies this disease under: 5C52.01

Codes checked against WHO ICD-11 and Orphanet on October 7, 2026.

This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.

The information on these pages is for general information only and does not replace medical advice. Talk to your doctor about diagnosis and treatment decisions. In an emergency in Türkiye, call 112.

Every update is based on an open source and labeled with its level of evidence. No advertising and no drug brand names. Our scientific principles

This page was translated from Turkish by the Doktorclub editorial team.