Krabbe disease

Alternative names:

globoid cell leukodystrophy

Definition:

An inherited disorder characterized by a deficiency of the enzyme galactocerebroside beta-galactosidase and a resulting destruction of myelin (a fatty material that surrounds many of the nerves).

Causes, incidence, and risk factors:

Krabbe disease is inherited as an autosomal recessive trait. It has a higher incidence among people of Scandinavian descent. Absence of the enzyme galactocerebroside beta-galactosidase causes the accumulation of galactocerebroside in the nervous tissue. Accumulating galactocerebroside results in increasing destruction of myelin. The end result is a progressive destruction of the nervous system.

Krabbe disease, like many other storage diseases, has an early onset form and a late onset form. In the early form, symptoms begin in the first months of life with feeding problems and failure to thrive, unexplained fevers, and vomiting. Changes in muscle tone are frequent, and seizures may begin very early and are severe. Visual and hearing losses are progressive. Affected children eventually assume a rigid unusual body position called decerebrate posturing. Death follows shortly thereafter, usually before the second year of life.

The late onset form of the disease begins in late childhood or early adolescence. Visual problems progressing to blindness may be the first symptom. Gait disturbance (ataxia) and muscle rigidity lead to progressive disability.