Definition

X-linked adrenoleukodystrophy (ALD) is a rare genetic disorder. In people with ALD, the body cannot properly break down fatty acids. This results in a build up of saturated fatty acids in the brain and the adrenal cortex. This causes damage to the myelin sheath in the brain and adrenal gland.

Myelin Sheath Around Nerve Fiber

AX00010_97870_1_myelin_sheath
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There are 6 subtypes:

  • Childhood cerebral ALD
  • Adolescent ALD
  • Adrenomyeloneuropathy
  • Adult cerebral ALD
  • Adrenal insufficiency-only
  • Symptomatic heterozygotes

Causes

An inherited defective gene causes ALD.

Risk Factors

Having family member with ALD raises your risk.

Symptoms

Symptoms differ within the types of ALD.

This form is the most severe. It is only in boys. Symptoms start between 2 to 10 years of age. Boys may have:

  • Behavioral changes
  • Poor memory
  • Slowed thinking and physical movements
  • Loss of skills

As the disease progresses, more serious symptoms begin, such as:

  • Problems seeing
  • Seizures
  • Hearing loss
  • Problems swallowing and speaking
  • Problems with walking and coordination
  • Vomiting
  • Lack of energy
  • More skin pigment
  • Progressive dementia
  • Vegetative state or death

This type is like the childhood type. It starts around 11-21 years of age. It happens more slowly.

This is the most common form. Symptoms of AMN can start in the 20's. It slowly gets worse. You may have:

  • Lack of strength, clumsiness, weight loss, and nausea
  • Emotional problems or depression
  • Motor/movement problems, such as walking problems
  • Urinary problems or impotence

With this type, symptoms usually do not appear until 20 or 50 years of age. It causes symptoms that are like schizophrenia and dementia. It gets worse quickly. Death or a vegetative state can happen in 3-4 years.

This form is only seen in women. Symptoms may be mild or severe. It usually does not affect the adrenal gland function.

Diagnosis

You will be asked about your symptoms and health history. A physical exam will be done.

Blood tests and genetic tests may be done.

Treatment

There is no known cure for brain damage from ALD. But the adrenal deficiency can be treated with cortisone replacement. ALD often causes death 10 years after symptoms start.

Some therapies can ease symptoms, such as:

  • Physical therapy
  • Mental health therapy
  • Special education for children

Prevention

ALD can’t be prevented. If you have ALD or have a family history of ALD, you can talk to a genetic counselor when deciding to have children.