The leukodystrophies are a group of rare, progressive, genetic diseases. The term leukodystrophy comes from the Latin roots leuko, meaning “white,” and dystrophy, meaning “impaired growth.” Leukodystrophy refers to progressive degeneration of the white matter of the brain as a result of imperfect growth or development of the myelin sheath. Most leukodystrophies become evident during childhood or adolescence, are incurable, and have a progressive course, leading to premature death. The most common presentation of a leukodystrophy is a gradual cognitive decline in a previously well-appearing infant or child; however, subtle presentations, including personality changes, can be the earliest signs and can precede the loss of previously acquired milestones and motor skills.

Symptoms vary according to the specific type of leukodystrophy and may be difficult to recognize ...