Krabbe disease or Globoid-cell leukodystrophy (GLD) is an inherited disorder caused by faulty genes passed on from parents to children. In GLD the body is missing the galactocerebrosidase enzyme needed to break down several types of fat-based compounds in the body. Without the enzyme the compounds build up in cells throughout the body. This build-up damages the myelin sheath, which is a substance that surrounds nerve cells. Without this myelin sheath the nerves in the brain and elsewhere cannot work properly.
Patients with GLD have difficulty with memory, learning, speaking, understanding and other mental functions. These patients also have poor muscle control, muscle weakness and stiff joints. Without treatment, this damage progresses and there is no treatment that can undo any damage that has already happened.
GLD is very rare with only about 40 children diagnosed in the United States each year. Symptoms begin in the first months of life (early onset) or in a less common form does not show until later in childhood or teen-age years (late onset).
The purpose of an allogenic transplant is to replace the patient’s defective blood forming cells missing the important enzyme with healthy blood forming cells from the normal donor who has the missing enzyme. Studies have demonstrated that this approach does provide normal levels of the missing enzyme for the patient. However, patients who were symptomatic at time of transplant all had disease progression after transplant. Those transplanted while presymptomatic had mixed results with some normal, but others showing mild-moderate language delays and mildly to severely impaired gross motor function.
Because children with GLD have mental and neurologic problems that get worse over time, it is best to have a transplant as soon as possible after diagnosis. Transplants for children with GLD who already have developed severe damage have poor results with little to no improvement or change in the disease progression. It is recommended that children with GLD be referred for transplantation as soon as they are diagnosed.