Adrenoleukodystrophy: What is it? Risk Factors, Types, Causes, Symptoms and Treatment

It refers to several hereditary conditions affecting the nervous system and the adrenal glands.

This severe brain disorder is sometimes called Addison’s disease or cerebral sclerosis. It mainly affects children and men. There is still no cure, but an early diagnosis in life can prevent it from getting worse.

The three main categories of Adrenoleukodystrophy are infantile cerebral Adrenoleukodystrophy, adrenomyelopathy, and Addison’s disease.

The gene that causes Adrenoleukodystrophy was identified in 1993. According to the Oncofertility Consortium, Adrenoleukodystrophy occurs in approximately 1 in 20,000 to 50,000 people and mainly affects men.

Women with the gene tend to be asymptomatic or mildly symptomatic, meaning there are no or very few symptoms.

The symptoms, treatments, and prognosis of Adrenoleukodystrophy vary according to the present type. Adrenoleukodystrophy is not curable, but doctors can sometimes slow down its progression.

What is Adrenoleukodystrophy?

Adrenoleukodystrophy causes severe damage to your nervous system. It does this by separating the covering of fat (called myelin) that protects the nerves in the brain and spinal cord. This makes it more difficult for the nerves to send messages to their brain.

 

The adrenal glands, which help control things like your immune system, blood pressure, and other functions, are also impaired by Adrenoleukodystrophy. Because of that, your body can not produce enough hormones to be healthy.

Risk factor’s

A gene mutated in the X chromosome (the DNA chain that decides whether a man or a woman is born) is the cause of Adrenoleukodystrophy.

Men have an X chromosome, so they only need to inherit a damaged gene from one of their parents. Women have two X chromosomes, so they are less likely to have Adrenoleukodystrophy. If they do, it is often less severe.

What are the different types of Adrenoleukodystrophy?

Adrenoleukodystrophy can come in several different forms. The symptoms will vary with each one but often get worse over time.

Cerebral demyelinating Adrenoleukodystrophy: 45% of people with Adrenoleukodystrophy have this type. It is the most severe form of Adrenoleukodystrophy. The symptoms often start between four and eight years and include:

  • Attention deficit disorder (ADD).
  • Problems with vision, hearing, and motor function.
  • Behavioral problems
  • Hyperactivity
  • Fatigue.
  • Clumsiness.
  • Low blood sugar
  • Eye pain.
  • Migraines .
  • Viral infections that keep coming back.
  • Skin darkened

Adrenomyeloneuropathy (AMN): this adult form of Adrenoleukodystrophy tends to have milder symptoms. About half of those who have it do not show signs until they are between 20 and 30. Even so, as Adrenoleukodystrophy, AMN can cause a severe loss of brain function. Some of the first signs are:

  • Problems with walking.
  • Balance problems
  • Changes in the way of walking.
  • Numbness or tingling in the legs.
  • Weakness of the arm
  • Feeling an urgent need to urinate or poop.
  • Incontinence.
  • Not being able to obtain or maintain an erection.

Addison’s disease: Over time, Adrenoleukodystrophy causes severe damage to the adrenal glands. This can not be reversed. Symptoms include:

Female Adrenoleukodystrophy: women who inherit the mutated gene that causes Adrenoleukodystrophy often do not have a brain disease but may show mild symptoms. Most of the time, these begin after 35 years. They can include:

  • Weakness.
  • Numbness.
  • Pain in the joints.
  • Urinary problems

Infantile cerebral Adrenoleukodystrophy: this type of Adrenoleukodystrophy is mainly found in children between 3 and 10 years old. This disease has a very rapid progression and results in severe disability for the child and, in some cases, even death.

Adrenomyelopathy: this type of Adrenoleukodystrophy affects men. This is a much milder form of Adrenoleukodystrophy and has a much slower progression.

Addison’s disease: this is another form of Adrenoleukodystrophy and is caused by adrenal insufficiency.

Causes

The protein Adrenoleukodystrophy (ALDP) helps your body break down very-long-chain fatty acids (VLCFA). If the protein does not work, the fatty acids accumulate inside your body. This can damage the outer layer of cells in your:

  • Spinal cord.
  • Brain.
  • Kidney glands.
  • Testicles

People with Adrenoleukodystrophy have mutations in the gene that produces Adrenoleukodystrophy protein. Their bodies do not produce enough protein for Adrenoleukodystrophy.

Men are usually affected by Adrenoleukodystrophy younger than women and generally have more severe symptoms. Adrenoleukodystrophy affects men more than women because it is inherited in a pattern linked to X.

This means that the responsible gene mutation is on the X chromosome. Men have only one X chromosome, while women have two. Because women have two X chromosomes can have a normal gene and a copy with the gene mutation.

Women with only one copy of the mutation have much milder symptoms than men. In some cases, women who carry the gene do not have any symptoms.

Your regular copy of the gene produces enough Adrenoleukodystrophy protein to help mask your symptoms. Most women with Adrenoleukodystrophy have adrenomyopathy.

Addison’s disease and infantile cerebral Adrenoleukodystrophy are less common.

Symptoms of Adrenoleukodystrophy

Symptoms of infantile cerebral Adrenoleukodystrophy include:

  • Muscle spasms.
  • Convulsions
  • Difficulty swallowing
  • Hearing loss.
  • Problems with language comprehension
  • Vision problems.
  • Hyperactivity
  • Paralysis.
  • Coma.
  • Impairment of fine motor control.
  • Eyes crossed.

Signs of Adrenomyelopathy  include:

  • Poor control of urination.
  • Weak muscles
  • Rigidity in the legs.
  • Difficulty thinking and remembering visual perceptions.

Signs of adrenal insufficiency or Addison’s disease include:

  • Little appetite
  • Weightloss.
  • Decrease in muscle mass.
  • Vomiting
  • Weak muscles
  • Coma.
  • Darker areas of skin color or pigmentation.

Diagnosis

The symptoms of Adrenoleukodystrophy can mimic those of other diseases. Tests are needed to distinguish Adrenoleukodystrophy from other neurological conditions. Your doctor may order a blood test to:

  • Look for abnormally high levels of VLCFA.
  • Check your adrenal glands
  • Find the genetic mutation that causes Adrenoleukodystrophy.

Your doctor may also look for damage to your brain using an MRI. Skin samples or a biopsy and culture of fibroblasts can also be used to evaluate VLCFA.

Children with suspected Adrenoleukodystrophy may need additional tests.

The disease may take a while to be diagnosed since it is possible that other diseases must first be ruled out.

Many early symptoms can be overlooked or blamed on more common and milder health problems, such as Attention Deficit Disorder (ADD) or learning disabilities.

If your doctor suspects Adrenoleukodystrophy, you can order two tests. One is a blood test that looks for a particular type of fatty acid that people with Adrenoleukodystrophy have in large quantities.

This test works better in men. It is not as accurate when used in women.

The other way to confirm Adrenoleukodystrophy is through an MRI (magnetic resonance). A brain scan can look for injuries (signs of damage) caused by the disease.

Based on your results, your doctor will assign you a “Loes score.” This measures the amount of brain damage seen on a scale of 0.5 (standard) to 34. Any level higher than 14 is a sign of severe Adrenoleukodystrophy.

Treatment

The methods of treatment depend on the type of Adrenoleukodystrophy you have. Steroids can be used to treat Addison’s disease.

There are no specific methods to treat the other types of Adrenoleukodystrophy. Some people have been helped by:

  • Switch to a diet that contains low levels of VLCFA.
  • Taking Lorenzo’s oil to help lower high levels of VLCFA.
  • Take medications to relieve symptoms such as seizures.
  • Doing physical therapy to relax the muscles and reduce spasms.

Doctors continue to seek new Adrenoleukodystrophy treatments. Some doctors are experimenting with bone marrow transplants.

If children with childhood cerebral adrenoleukodystrophy are diagnosed early, these experimental procedures can help.

Bone marrow transplant: Children with early signs of Adrenoleukodystrophy may benefit from this procedure. A donor’s healthy red blood cells can help prevent further damage to myelin.

The process can take months, and recovery is long, but children who receive a transplant early enough can have daily or near-normal lives.

Gene therapy: this new treatment removes damaged stem cells, repairs the “defective” gene that causes Adrenoleukodystrophy, and then recovers a healthy version.

It carries less risk than a bone marrow transplant, but more research is needed before it is widely used.

Steroids: a daily pill can help control Addison’s disease.

Physiotherapy: if walking is a problem, a physiotherapist can provide exercises to help you strengthen your muscles and make them less painful.

Lorenzo’s oil: this mixture of rapeseed oil and olive oil prevents the body from producing certain fatty acids that cause the myelin to decompose.

Although it may delay the onset of Adrenoleukodystrophy in children, the Food and Drug Administration has not yet approved Lorenzo’s oil. It is also not clear if it helps men with AMN.

Prospects of Adrenoleukodystrophy

Infant cerebral Adrenoleukodystrophy can cause severe disability, coma, and death. The coma typically occurs around two years after the symptoms appear and can last up to 10 years until death.

Adrenomyelopathy and Addison’s disease are not as severe as infant cerebral Adrenoleukodystrophy. They progress at a slower pace. Symptoms can be treated, but there is no cure for Adrenoleukodystrophy.

Prevention

Because Adrenoleukodystrophy is a hereditary condition, there is no way to prevent it. If you are a woman with a family history of Adrenoleukodystrophy, your doctor will recommend genetic counseling before having children.

An amniocentesis or a chorionic villus sample may be performed during pregnancy to determine if your unborn child is affected.