DefinitionAdrenoleukodystrophy describes several closely related inherited disorders that disrupt the breakdown (metabolism) of certain fats (very-long-chain fatty acids).
Alternative NamesAdrenoleukodystrophy; Adrenomyeloneuropathy; Childhood cerebral adrenoleukodystrophy; ALD; Schilder-Addison Complex
Causes, incidence, and risk factorsAdrenoleukodystrophy is passed down from parents to their children 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 lifeImpaired adrenal gland function (called Addison disease or Addison-like phenotype) -- adrenal gland does not produce enough steroid hormones
SymptomsChildhood cerebral type:Changes in muscle tone, especially muscle spasms and spasticityCrossed eyes (strabismus)Decreased understanding of verbal communication (aphasia)Deterioration of handwritingDifficulty at schoolDifficulty understanding spoken materialHearing lossHyperactivityWorsening nervous system deterioration
ComaDecreased fine motor controlParalysisSeizuresSwallowing difficultiesVisual impairment or blindnessAdrenomyelopathy:Difficulty controlling urinationPossible worsening muscle weakness or leg stiffnessProblems with thinking speed and visual memoryAdrenal gland failure (Addison type):ComaDecreased appetiteIncreased skin color (pigmentation)Loss of weight, muscle mass (wasting)Muscle weaknessVomiting
Signs and testsBlood levelsChromosome study to look for changes (mutations) in the ABCD1 geneMRI of the head
TreatmentAdrenal dysfunction is treated with steroids (such as cortisol).A specific treatment for X-linked adrenoleukodystrophy is not available, but eating a diet low in very-long-chain fatty acids and taking special oils can lower the blood levels of very-long-chain fatty acids.These oils are called Lorenzo's oil, after the son of the family who discovered the treatment. This treatment is being tested for X-linked adrenoleukodystrophy, but it does not cure the disease and may not help all patients.Bone marrow transplant is also being tested as an experimental treatment.
Expectations (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.
ComplicationsAdrenal crisisVegetative state (long-term coma)
Calling your health care providerCall your health care provider if:Your child develops symptoms of X-linked adrenoleukodystrophyYour child has X-linked adrenoleukodystrophy and is getting worse
PreventionGenetic counseling is recommended for prospective parents with a family history of X-linked adrenoleukodystrophy. Female carriers can be diagnosed 85% of the time using a very-long-chain fatty acid test and a DNA probe study done by specialized laboratories.Prenatal diagnosis of X-linked adrenoleukodystrophy is also available. It is done by evaluating cells from chorionic villus sampling or amniocentesis.
ReferencesKwon 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.