Updated September 20, 2019

This article was scientifically reviewed by YourDNA

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What is VLCAD?

VLCAD goes by two abbreviations — VLCAD and VLCADD — but both refer to the same rare genetic disease: very long-chain acyl-CoA dehydrogenase deficiency.

Whether you choose to call the disease VLCAD deficiency or just VLCADD, you should know that this uncommon disease impacts how the body breaks food down into energy.

What's in this Guide?

Disclaimer: Before You Read

It is important to know that your genes are not your destiny. There are various environmental and genetic factors working together to shape you. No matter your genetic makeup, maintain ideal blood pressure and glucose levels, avoid harmful alcohol intake, exercise regularly, get regular sleep. And for goodness sake, don't smoke.

Genetics is a quickly changing topic.

It’s a serious disease that can have lasting health effects if not treated promptly or properly.

What is VLCADD deficiency?

So, just what is this genetic disease with an extremely long name? VLCADD is considered a fatty acid oxidation disorder, meaning that the disease impacts how the body breaks down fatty acids.

That means people with VLCADD have difficulty with their body turning certain kinds of fat into energy.

VLCADD can be especially dangerous if undiagnosed because it allows the body to build up fatty acids.

This can lead to a variety of health issues, including liver enlargement and abnormalities and heart problems such as arrhythmias and heart disease. VLCADD can also lead to muscle tissue breakdown.

It’s estimated that approximately 1 in 30,000 to 40,000 people have VLCADD, and people of any age can be diagnosed. In fact, there are three types of VLCADD:

  1. Early-onset VLCADD (diagnosed in infants)
  2. Hepatic or Hypoketotic hypoglycemic VLCADD (diagnosed in children)
  3. Later-onset episodic myopathic VLCADD (diagnosed in adults)

VLCADD is caused by mutations of the ACADVL gene and is passed from parent to child.

In many cases, both parents may be carriers of the ACADVL gene mutation, but may not have VLCADD themselves. Doctors diagnose VLCADD most commonly in adults.

Signs & Symptoms of VLCADD

VLCADD can be diagnosed at any stage of life. Symptoms and their severity often vary from person to person.

It’s not unusual for a VLCADD diagnosis to be missed or attributed to other health issues simply because the disease is so rare.

In general, VLCAD disease symptoms may present differently based on the age and health of the patient.

Early-onset VLCADD (also known as infant VLCADD) symptoms usually appear within the first year of a child’s life, while hepatic or hypoketotic hypoglycemic VLCADD is usually diagnosed in older children.

VLCAD symptoms in babies and children include:

  • Pericardial effusion (fluid surrounding the heart)
  • Heart arrhythmias (out-of-pattern or unusual heartbeat)
  • Low muscle tone
  • Enlarged liver
  • Hypoglycemia
  • Cold, clammy skin
  • Weakness or shakiness
  • Dizziness
  • Behavior changes and irritability
  • Diarrhea
  • Intense sleepiness or exhaustion
  • Weak muscles
  • Difficulty breathing

Because VLCADD can appear later in life, adults with the following symptoms should seek medical attention to determine if they may have later-onset episodic myopathic VLCADD:

  • Muscle breakdown and weakness
  • Muscle cramps and pain
  • Exercise intolerance
  • Lethargy and extreme exhaustion
  • Enlarged liver
  • Difficulty breathing

Delaying treatment for VLCADD can lead to lasting health effects, so it’s important to promptly speak with your doctor if you or your child are experiencing these symptoms.

Causes of VLCADD

VLCADD is a deficiency that is passed genetically from parent to child through a mutation in the ACADVL gene, which tells the body how to the VLCAD enzyme.

This enzyme is necessary because it helps the body metabolize and break down fats through a process called fatty acid oxidation, which converts fats to energy.

Fatty acids are necessary because they give the body fuel and support the heart, muscles, and liver to work properly.

Being diagnosed with VLCAD deficiency means that a person’s body is unable to break down fats because their ACADVL gene has a mutation preventing the body from doing so.

VLCADD is not contagious, and cannot be transferred from person to person. The only way to develop VLCADD is to have inherited it genetically.

Inheritance Pattern of VLCADD

VLCADD is considered an autosomal recessive condition, meaning that both parents must carry the ACADVL gene mutation for their child to inherit the disease.

If a parent has this genetic mutation, they can be carriers for VLCADD, but may not have the condition or symptoms themselves.

According to the National Institutes of Health’s Genetic and Rare Diseases Information Center, if both parents have the ACADVL mutation, their children have a 25% chance of inheriting the condition.

But, it is possible to have two carrier parents and not develop VLCADD — in fact, children with carrier parents have a 50% chance of being carriers of the gene mutation like their parents, but with no health issues, and a 25% chance of not being a carrier or having the condition at all.

Risk Factors for VLCADD

Because VLCADD is a genetically inherited disorder, people who are carriers of the ACADVL gene mutation have the highest chance of passing on the gene and disorder to their children.

This is true for both people who have the gene mutation but do not have VLCADD, as well as people who have VLCADD and have a partner or spouse who is also the carrier of the ACADVL mutation.

Who does VLCADD typically affect?

While almost anyone can be diagnosed with VLCADD, some groups that have a higher risk of carrying or inheriting the disorder, including:

  • People whose parents both carry the ACADVL genetic mutation
  • People with a family history of ACADVL genetic mutation or VLCADD diagnosis
  • People with Pacific Island ancestry (researchers are unsure why this ethnic group has a higher rate of occurrence than other ethnic groups)

Possible Complications of VLCADD

VLCADD can be especially dangerous in infants and young children, and can lead to life-altering conditions or the risk of death.

If undiagnosed, the childhood form of VLCADD causes metabolic crisis — a dangerous condition caused by low blood sugar and the buildup of toxic substances in a person’s blood, which can lead to seizures, difficulty breathing, coma, or even death.

Symptoms of metabolic crisis include diarrhea, unusual sleepiness, behavior changes, nausea, and vomiting.

One of the biggest risks is VLCAD cardiomyopathy, a disease that makes it difficult for the heart to pump and circulate blood.

This disease can be reversed thanks to medications and supplements that counter the effects of VLCAD.

VLCADD can also interact with other illnesses to create health situations that require hospital admittance or emergency care.

VLCAD and flu do not interact well, simply because the virus makes it difficult for people to get in and keep enough nutrients in their body.

For people with VLCAD, long portions of time without food can be dangerous, leaving the body without the energy it needs to fight off sickness.

A doctor may recommend that a person with VLCAD seek hospitalization for illnesses, such as the flu, to prevent complications.

In situations where surgery is needed, VLCAD and anesthesia often do not mix well. Some forms of anesthesia, such as propofol and volatile anesthetics, can impact the body’s metabolism.

When mixed with fasting, which is often required before some medical procedures but unhealthy for people with VLCADD, anesthesia use can have dangerous complications that lead to death.

Related Disorders

While VLCADD is relatively rare, other health conditions that can present similar symptoms. Some related disorders include:

  1. Long chain fat oxidation defects — because several genes play a role in fatty acid oxidation, it’s possible for a person with VLCADD to be diagnosed with a different gene mutation. That’s because many genes in this group can often present similar symptoms.
  2. Galactosemia — another rare condition, galactosemia shows similar symptoms to VLCADD. That’s because the disease makes it difficult for the body to break down sugars, which build up in the blood and can lead to liver failure and impaired brain development.
  3. Reye syndrome — this rare condition most often occurs in children ages 4 to 12, and causes fat to build up in the liver and sudden brain swelling. This condition can share some similar bloodwork results to VLCADD.

Diagnosis of VLCADD

Because VLCADD is a genetic disorder, doctors often rely on blood tests to observe a patient’s DNA and look for an ACADVL gene mutation.

Doctors may also rely on other tests to back up information they receive from blood and DNA tests, including skin and liver biopsies, muscle biopsies, and urine tests.

This information, in combination with observing possible VLCADD symptoms, can help doctors determine if you have VLCADD at any stage of life, including right at birth to childhood and beyond.

Testing for VLCADD

If a doctor believes you may have VLCADD, you’ll likely undergo a variety of tests to confirm the diagnosis or rule it out altogether.

The kinds of tests your doctor chooses to perform will depend on a variety of factors but can range between blood tests, DNA testing, urine test, and biopsies of skin, liver, and muscle tissue.

Is genetic testing available?

Yes. Your doctor may want to use genetic testing to determine if you or your child carry the ACADVL gene mutation.

These tests will be performed by drawing a blood sample and sending it to a diagnostic lab to determine if the gene mutation is present.

Other testing available

There are several kinds of tests that a doctor may utilize to determine if you or your child have VLCADD. These tests include:

  • Blood tests — this form of testing allows doctors to monitor the makeup of your blood to determine if there is a buildup of fatty acids, other nutrients, and toxins
  • Urine tests — observing urine samples allows a doctor to determine how well the kidneys may be functioning, and if there is fatty acid and toxin buildup
  • Tissue biopsies — gathering small amounts of liver, skin, and muscle tissue can help doctors determine if these areas of your body are having difficulty filtering out toxins, or if they are being weakened by VLCADD

Testing during pregnancy

If you suspect that the unborn child you are carrying may have this genetic disorder, it is possible to test for VLCAD in pregnancy.

This test is done through an amniocentesis, a procedure that collects amniotic fluid and uses the DNA information it contains for testing.

Carrier testing

If you believe you or a spouse may be a carrier of the gene mutation that causes VLCADD, know that genetic carrier testing is available.

Done through a blood draw, a genetics testing lab can determine if you and a partner are carriers of the ACADVL gene mutation — which can help you make informed decisions about having biological children.

Understanding the Test Results

Because VLCADD testing must be done through a doctor’s office or hospital (at this time no at-home tests can determine if you have this genetic mutation), one benefit of understanding the results is that your physician will be able to explain just what they mean.

By combining a variety of diagnostic tests with DNA testing, your doctor should have strong evidence about whether or not you have VLCADD.

Still, you should know that it is possible to have a VLCAD false positive. That’s because blood tests are the most commonly used tests for screening newborn babies.

Some babies who are carriers of VLCADD but do not have the disease can trigger a false positive that requires further genetic testing.

You should know, however, that it is very difficult to have false positive from a VLCADD genetic test because a gene mutation is either present or not present.

Treatment Options for VLCADD

VLCADD is mostly treated through diet and medications. One of the most important factors in managing VLCADD is understanding how your body metabolizes food, and how often you must eat to give your body nutrition and fuel.

Many people with VLCADD work with dieticians to create specialty diets that restrict fat intake and boost carbohydrates.

A VLCAD diet works by limiting fatty acid buildup and increasing the kinds of fuel the body can digest and use.

VLCAD foods to avoid usually include fatty meats, high-fat dairy, and processed foods, while encouraged foods usually include bread, pasta, fruits, and vegetables.

VLCAD in babies can be scary to manage, but can be done so through proper nutrition, both during the infant stage and after babies start solid foods.

With VLCAD breastfeeding is possible, so long as milk supply remains adequate and regular feeding occurs.

Many people with VLCADD are also prescribed dietary supplements to ensure they are getting all of the fats and nutrients their bodies need.

This is especially important in young children since fatty acids help with brain development and growth.

People diagnosed with VLCADD often benefit from this modified diet and can reduce the effects of complications caused by VLCADD.

You should know that there is no VLCAD medication to cure this condition

While there is no specific medication for VLCAD, a doctor will determine if you need medications to help your heart and liver or reduce complications the disease has on your body.

Prognosis for VLCADD

When it comes to VLCADD diagnosis in infants, many people wonder, “Is VLCAD deadly?” You should know that the condition can be fatal if not identified and treated promptly.

But thanks to more modern newborn screenings and blood testing, it has become easier for hospitals and doctors to identify potential cases of VLCADD.

Quick treatment can also prevent heart and organ problems that can be life-threatening; if these conditions have appeared, nutritional changes and symptom treatment can reduce their effects.

Because VLCADD is rare, and the severity can differ from person to person, it’s difficult for doctors and researchers to predict if the condition impacts a person’s lifespan or quality of life.

And since the disease only occurs in about 1 of every 40,000 people, the VLCAD mortality rate is unknown.

Still, people who are diagnosed with VLCADD before symptoms become life-threatening generally have a good outlook if they follow recommendations on nutrition, medication, and treatment of symptoms.

What To Do Next

If you’ve been diagnosed with VLCADD, you should know that treatment is often lifelong, but your quality of life doesn’t have to diminish.

Many people with the disease who stick to a VLCAD food list and follow their doctor’s recommendations live full lives.

If you’re wondering what comes after a VLCADD diagnosis, know that disease management takes some adjustment, and may require regular testing.

Fully understanding VLCAD and how it impacts you can help you make healthy choices moving forward.

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