Adrenoleukodystrophy (also known as
X-linked adrenoleukodystrophy,
ALD,
X-ALD,
adrenomyeloneuropathy,
AMN,
Siemerling–Creutzfeldt disease or
bronze Schilder disease) is a disorder of peroxisomal fatty acid beta oxidation which results in the accumulation of
very long chain fatty acids in tissues throughout the body. The most severely affected tissues are the
myelin in the
central nervous system, the
adrenal cortex and the
Leydig cells in the testes. Clinically, ALD is a heterogenous disorder, presenting with several distinct
phenotypes, and no clear pattern of
genotype-phenotype correlation. As an X-linked disorder, ALD presents most commonly in males, however approximately 50% of
heterozygote females show some symptoms later in life. Approximately two-thirds of ALD patients will present with the childhood cerebral form of the disease, which is the most severe form. It is characterized by normal development in early childhood, followed by rapid degeneration to a
vegetative state. The other forms of ALD vary in terms of onset and clinical severity, ranging from adrenal insufficiency to progressive
paraparesis in early adulthood (this form of the disease is typically known as adrenomyeloneuropathy).