肾上腺脑白质失养症（ALD, Adrenoleukodystrophy），是一种脑内去髓鞘化白质化的遗传病，其通常分作儿童型脑白质化、青少年大脑型、肾上腺脊髓性神经病变型及女性异型合子病征基因型。患者细胞的过氧化体在代谢较长的链脂肪酸时产生异常，尤其是C24、C26长链脂肪酸会异常堆积在大脑的白质和肾上腺的皮质内，进而侵蚀患者脑神经系统的髓鞘质，造成患者的髓鞘脱失，脑部的神经细胞因此就会被摧毁，进而妨碍神经的传导。

Adrenoleukodystrophy (/-ˌlu-koʊ-ˈdis-trə-fiː/; also known as X-linked adrenoleukodystrophy, ALD, X-ALD, adrenomyeloneuropathy, AMN, Siemerling–Creutzfeldt disease or bronze Schilder disease) is a disease that is linked on the X chromosome. It is a result of fatty acid digestive enzymes not breaking up the fats. These fats build up in the brain. They damage the myelin that surrounds nerves. This can cause seizures and hyperactivity. It can also cause problems with speaking, listening and understanding verbal instructions.