MCAD deficiency

By Medically reviewed by Hello Doktor Medical Panel


What is MCAD deficiency?

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is an inherited disorder that prevents your body from breaking down certain fats and converting them into energy. As a result, the level of sugar in your blood can drop dangerously low. MCAD deficiency is present from birth.

How common is MCAD deficiency?

The condition is more common in people of northern European ancestry than in other ethnic groups. Please discuss with your doctor for further information.


What are the symptoms of MCAD deficiency?

Signs and symptoms typically first appear in babies and young children. The disorder can lead to early health problems, such as vomiting and lack of energy. With MCAD, a defect (mutation) in your genes changes the way your body breaks down some fats. Genetic testing can reveal whether you have these mutations.

Signs and symptoms of the disorder are often triggered when an affected person goes too long without eating. Viral infections also can cause MCAD deficiency-related reactions.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes MCAD deficiency?

MCAD deficiency is caused by mutations in the ACADM gene. This gene gives the body instructions for making an enzyme called medium-chain acyl-CoA dehydrogenase, needed to break down fats called medium-chain fatty acids. These fatty acids are found in foods and the body’s tissues, and are an important source of energy for the heart, muscles, liver, and other tissues. Mutations in this gene lead to low levels of the enzyme, which means that medium-chain fatty acids are not broken down properly. They cannot be converted to energy, leading to the symptoms of MCADD.

Risk factors

What increases my risk for MCAD deficiency?

You must inherit the affected genes from both of your parents. If you inherit only one affected gene, you won’t develop MCAD deficiency. With one affected gene, you are a gene mutation carrier and can pass the mutation on to your children. But they wouldn’t develop the condition unless they also inherited an affected gene from the other parent.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How is MCAD deficiency diagnosed?

A diagnosis of MCADD requires an evaluation of a person’s symptoms as well as the interpretation of several tests. Initial testing may include:

  • Plasma acylcarnitine
  • Urine organic acid
  • Urine acylglycine

Further testing to confirm the diagnosis may include molecular genetic testing of the ACADM gene or biochemical genetic testing.

MCADD is included in many newborn screening programs, so a newborn with MCADD who does not yet exhibit symptoms may be diagnosed early. If a newborn screening result for MCADD is not in the normal range (“positive”), additional testing can then be ordered.

How is MCAD deficiency treated?

The main goal of treatment for MCAD deficiency is to prevent problems from occurring. It’s important to have regular meals and snacks and choose foods that are high in carbohydrates and low in fat.

Talk with your doctor about what to do if symptoms develop. Some experts recommend giving simple carbohydrates, such as glucose tablets or sweetened, non-diet beverages, by mouth. If the symptoms are more serious, an intravenous (IV) line may be needed.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage MCAD deficiency?

Please discuss with your doctor for further information.

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Share now :

Review Date: November 21, 2017 | Last Modified: December 8, 2019

You might also like