An inherited metabolic disorder that negatively affects the body’s ability to convert certain fats into energy is called MCAD (medium-chain-coenzyme A dehydrogenase) deficiency. The symptoms usually appear after a long period of fasting (without eating). They often include tiredness, nausea, low blood sugar, and others. Physicians usually treat MCAD deficiency with frequent meals and a diet full of complex carbohydrates.
In normal circumstances, the body produces specific enzymes that help process foods. These enzymes target a group of fats (called medium-chain fatty acids) to convert them into a substance that the body uses as energy. However, in people with MCAD deficiency, there are reduced or a lack of these enzymes, which affects the body’s ability to metabolize these fatty acids.
Typically, this condition occurs quite rarely and affects about 1 in every 15,000 people.
How Will MCAD Deficiency Affect My Baby’s Body?
This condition affects the baby’s ability to turn fat into energy. Thus, if the baby’s energy needs are not met, it may lead to symptoms, especially during an illness. These include tiredness, feeling sick, nausea, and others.
Symptoms
The symptoms of this condition range from mild to severe, and they often appear during early infancy and childhood and can be triggered during an illness when the child loses appetite. Check some examples below:
- Hypoglycemia (low blood sugar)
- Lethargy (low energy)
- Vomiting
- Muscle weakness
- Difficulty breathing
- Brain damage
- Liver problems
- Seizures
- Coma
If you or your child has any of the symptoms listed above, immediately contact your healthcare provider. Otherwise, it may lead to serious complications.
Causes
This health condition is caused by a mutation in the ACADM gene. This gene is responsible for the production of medium-chain acyl-CoA dehydrogenase. This is an enzyme that helps break down medium-chain fatty acids. Moreover, these fatty acids are found in food and later reside in the tissues. They are very important for the body because they are converted into energy, which is vital for the body structures and organs, including the heart, liver, muscles, and other tissues. The genetic mutation that causes MCAD deficiency cannot be prevented because it occurs randomly. In other words, people get this condition through an autosomal recessive pattern. It means you get the 2 abnormal genes, one from each biological parent, during pregnancy. If you get only one abnormal gene, it is less likely you will develop MCAD deficiency symptoms, but you can pass it to your children in the future. Unfortunately, there is no way to prevent gene mutation.
Risk Factors
Certain factors could increase your risk of developing MCAD deficiency. Check some examples below:
- Viral infections – Sometimes, these infections can cause appetite changes or vomiting that trigger a metabolic crisis.
- Metabolic stress – It is often caused by surgeries, severe health conditions, and high-fat/low-carbohydrate diets.
- Genetic inheritance – To pass this condition to children, both parents must carry the abnormal ACADM gene.
- Prolonged fasting – The risk of developing MCAD deficiency is higher in infants and young children when fasting (particularly when weaning or during nighttime).
What Are The Potential Complications of MCAD Deficiency?
Those who ignore the symptoms or do not get treatment for this condition may experience some complications. Check some examples below:
- Hypoketotic hypoglycemia – This is a complication that causes extremely low blood sugar, which is a main cause of acute symptoms.
- Neurological damage – For example, lethargy, coma, seizures, vomiting, and permanent brain injury caused by an acute metabolic crisis.
- Organ dysfunction – Some people may also experience severe liver disease (that is often mistaken for Reye’s syndrome), kidney damage, and metabolic acidosis.
- Cardiovascular problems – One of them is arrhythmia (irregular heart rhythm).
- Developmental delays – This complication often affects infants and children.
- Chronic effects – These include muscle weakness, long-term (chronic) myopathy, and an increased risk of obesity.
- Death – The risk of death significantly increases when people do not get treatment as soon as possible.
This article does not contain a complete list of complications. However, you can talk with your doctor about measures to reduce the risk of developing them. In addition, there is no way to prevent MCAD deficiency because it is a genetic disorder that passes from parents to their biological children. For more details, discuss it with your healthcare professional.
Diagnosis
In most cases, newborn screenings identify all health conditions that negatively affect your child’s overall health. Physicians often perform tests for this condition during a newborn screening. It means doctors can confirm the diagnosis before any symptoms appear. Furthermore, they may also perform a genetic test to check for the abnormal gene that causes this disorder. During this test, they will take a sample of blood, urine, or tissue.
Treatment
Doctors often prescribe treatments that meet nutritional requirements for people with MCAD deficiency. They may also reduce the long periods of time between meals, which may lead to symptoms. These include:
- Scheduling meals more frequently during the day
- Add to your diet foods high in carbohydrates
- Avoid excessive fat in the child’s diet
- Doctors may also recommend Carnitine supplements to assist conversion from fatty acids to energy
Physicians may also recommend limiting or avoiding alcoholic beverages because they can cause severe symptoms (metabolic crisis). In any case, if it happens, you should administer a glucose supplement or eat foods high in sugar.
Frequently Asked Questions
How do I manage symptoms of MCAD deficiency?
Mostly, the symptoms of this genetic disorder appear after prolonged fasting (long-term without food). That’s why doctors often recommend eating complex carbohydrates, including whole grains, vegetables, and beans. It may help relieve the symptoms.
When should I go to the ER?
Immediately call 911 or go to the nearest emergency room (ER) if any of the following symptoms occur. For example, confusion, seizures, anxiety, fear without a visible cause, loss of consciousness, and uncontrollable movement of the arms or legs.
What is the life expectancy of someone with MCAD?
People with MCAD deficiency often have a normal lifespan if the condition is diagnosed soon after birth and they get lifelong management. Otherwise, this condition can be fatal, especially in early childhood. Ask your healthcare provider if you have any other questions.
