The different forms of Krabbe disease are allelic. Symptoms usually start at three to six months of age. Development may be normal up to that time. Children then have a more severe and rapid deterioration of mental and motor function. Eventually children lose mental and motor function, become deaf and blind, cannot move or speak, and typically must be fed through a tube.
Death usually occurs within one year after symptoms appear.
Juvenile Krabbe disease. Loss of mental function and vision, paralysis on one side of the body, and difficulty in walking or other motor performance may be seen. Initially symptoms progress rapidly but then the rate of deterioration is much slower than for the infantile form. Symptoms may last five years or longer. Adult Krabbe disease.