X-linked adrenoleukodystrophy (ALD) is a rare inherited genetic disorder. There are 40 subtypes of leukodytsrophy. X-linked ALD is the most common category. ALD results in degeneration of the:

  • Myelin sheath— the fatty insulation covering on nerve fibers in the brain
  • Adrenal gland and surrounding adrenal cortex—produces vital hormones
Myelin Sheath Around Nerve Fiber
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There are six subtypes of X-linked ALD:

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

ALD is caused by an inherited defective gene.

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 of the myelin sheath in the brain and the adrenal gland.