The animated videos in NORD’s Rare Disease Video Library provide brief introductions to rare disease topics for patients, caregivers, students, professionals and the public. NORD collaborates with medical experts, patient organizations, videographers and Osmosis to develop the videos, which are made possible by individual donations, educational grants and corporate sponsorships. NORD is solely responsible for the content.
Summary
X-linked adrenoleukodystrophy (ALD) is a rare genetic disorder that affects the white matter of the nervous system and the adrenal cortex. White matter is made up of nerve fibers called axons that relay nerve impulses from one cell to another. These nerve fibers are covered by myelin, an insulating layer or sheath that protects the nerve fibers. Myelin is made up of proteins and fats and gives white matter its white color. Without myelin, the signals between nerve cells cannot be transmitted properly, resulting in neurological symptoms. The adrenal cortex is the outer layer of cells of the adrenal glands. The adrenal glands sit atop the kidneys and produce hormones that are vital to proper health and development including cortisol and the sex hormones. Many of those affected experience serious neurological problems either during childhood or during adulthood with rather different types of disabilities. Some affected individuals also have adrenal insufficiency, which means that reduced amounts of certain hormones such as adrenaline and cortisol are produced, leading to abnormalities in blood pressure, heart rate, sexual development and reproduction. ALD is an X-linked recessive disorder that is caused by variations (mutations) in the ABCD1 gene. Because it is an X-linked disorder males develop more serious complications than females, while some females will have no symptoms. ALD can be broken down into different types based on symptoms and age of onset.
