Adrenoleukodystrophy

 

Alternative Names

X-linked Adrenoleukodystrophy; Adrenomyeloneuropathy; Childhood cerebral adrenoleukodystrophy; ALD; Schilder-Addison Complex

Definition

Adrenoleukodystrophy describes several closely related inherited disorders that disrupt the breakdown (metabolism) of certain fats (very long chain fatty acids).

Causes

Adrenoleukodystrophy is usually passed down from parent to child as an X-linked genetic trait. It therefore affects mostly males, although some women who are carriers can have milder forms of the disease. It affects approximately 1 in 20,000 people from all races.

The condition results in the buildup of very-long-chain fatty acids in the nervous system, adrenal gland, and testes, which disrupts normal activity. There are three major categories of disease:

  • Childhood cerebral form -- appears in mid-childhood (at ages 4 - 8)
  • Adrenomyelopathy -- occurs in men in their 20s or later in life
  • Impaired adrenal gland function (called Addison disease or Addison-like phenotype) -- adrenal gland does not produce enough steroid hormones

Symptoms

Childhood cerebral type:

  • Changes in muscle tone, especially muscle spasms and spasticity
  • Crossed eyes (strabismus)
  • Decreased understanding of verbal communication (aphasia)
  • Deterioration of handwriting
  • Difficulty at school
  • Difficulty understanding spoken material
  • Hearing loss
  • Hyperactivity
  • Worsening nervous system deterioration, including coma, decreased fine motor control, and paralysis 
  • Seizures
  • Swallowing difficulties
  • Visual impairment or blindness

Adrenomyelopathy:

  • Difficulty controlling urination
  • Possible worsening muscle weakness or leg stiffness
  • Problems with thinking speed and visual memory

Adrenal gland failure (Addison type):

  • Coma
  • Decreased appetite
  • Increased skin color (pigmentation)
  • Loss of weight, muscle mass (wasting)
  • Muscle weakness
  • Vomiting

Exams and Tests

  • Blood levels of very long chain fatty acids and hormones that are produced by the adrenal gland
  • Chromosome study to look for changes (mutations) in the ABCD1 gene
  • MRI of the head

Treatment

Adrenal dysfunction my be treated with steroids (such as cortisol) if the adrenal gland is not producing enough hormones.

A specific treatment for X-linked adrenoleukodystrophy is not available, but bone marrow transplantation can be performed and can cure patients of the condition.

Outlook (Prognosis)

The childhood form of X-linked adrenoleukodystrophy is a progressive disease. It leads to a long-term coma (vegetative state) about 2 years after nervous system symptoms develop. The child can live in this condition for as long as 10 years until death occurs.

The other forms of this disease are milder.

Possible Complications

  • Adrenal crisis
  • Vegetative state (long-term coma)

When to Contact a Medical Professional

Call your health care provider if:

  • Your child develops symptoms of X-linked adrenoleukodystrophy
  • Your child has X-linked adrenoleukodystrophy and is getting worse

Prevention

Genetic counseling is recommended for prospective parents with a family history of X-linked adrenoleukodystrophy. Mothers of affected sons have an 85% chance of being a carrier for this condition.

Prenatal diagnosis of X-linked adrenoleukodystrophy is also available. It is done by evaluating cells from chorionic villus sampling or amniocentesis for either a known genetic change in the family or for very long chain fatty acid levels.

References

Kwon JM. Neurodegenerative disorders of childhood. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 592.

Steinberg SJ, Moser AB, Raymond GV. X-Linked adrenoleukodystrophy. GeneReviews™ [serial online]. Updated April 19, 2012. Available from: http://www.ncbi.nlm.nih.gov/books/NBK1315/

Review Date: 10/29/2013
Reviewed By: Chad Haldeman-Englert, MD, FACMG, Wake Forest School of Medicine, Department of Pediatrics, Section on Medical Genetics, Winston-Salem, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.

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