Adrenoleukodystrophy (ALD) is a rare, inherited, genetic disorder that affects the nervous system and adrenal glands. It is estimated to affect 1 in 18,000 to 21,000 people worldwide. ALD is caused by a mutation in the ABCD1 gene, which is located on the X chromosome. This mutation disrupts the body's ability to break down certain fatty acids, leading to an accumulation of these fatty acids in the brain, adrenal glands, and other organs. The symptoms of ALD can vary greatly from person to person, and may include intellectual disability, seizures, vision loss, hearing loss, and a decline in muscle coordination. Treatment for ALD can include dietary changes, physical therapy, occupational therapy, and medications. In some cases, a bone marrow transplant may be recommended.