What is Krabbe Disease?

I read that Jim Kelly (former quarterback of the Buffalo Bills) just had a son that was diagnosed with Krabbe Disease. Is this a genetic condition? Jennifer Thomas, Greenwood, South Carolina

Dear Ms. Thomas, it was in 1916 that Dr. Krabbe (Crab-beigh) first described two Danish infants with this progressive and invariably fatal condition. He noted that the infants developed stiffness in their joints soon after birth. They were irritable babies, very sensitive to light and sound, and seizures were common. The underlying cause of this genetic condition is now known.

Krabbe disease is a type of lysosomal storage disorder. The human body contains about two hundred different cell types. Each cell type carries out certain tasks, almost like little factories making specific parts for our growth and development. The cells break down molecules and structures as well as produce them. Structures within the cell called lysosomes are the "garbage disposal sites"; they break down fats, carbohydrates, invading bacteria and other debris. If the lysosomes are not working properly, the cells begin to accumulate the waste material. Almost like a blocked pipe, the build up of waste swells the cells, and blocks the normal cellular function.

In Krabbe disease, a specific enzyme within the lysosome, galactosylceramidase (galac-to-sil-seer-a-mid-ase), is deficient. The cellular garbage starts to build up from birth, especially in brain tissue. Under the microscope, characteristic large, fatty ("foamy") deposits are seen. As the disease progresses, these cells die, cutting off the connections between the brain and its nerve extensions. The brain becomes reduced in size, as both mental and physical function is lost. The progressive brain abnormalities cause the infant to have seizures, spasticity, hypersensitivity and, ultimately cause death around two years of age. Unfortunately, at this time there is no treatment, only supportive care for these infants.

The disease incidence appears to be higher in individuals from Scandinavian descent. In these populations, approximately 1 in 200,000 liveborn infants have Krabbe disease. As an autosomal recessive genetic condition, an individual must inherit a copy of an altered, nonworking gene from each parent to have the disease. Carrier parents would have one altered copy and one normal copy of the gene. The one normal copy produces enough enzyme so that they have no symptoms. There is a 1 in 4 (25%) chance, with each pregnancy, that the child may receive the altered gene from each carrier parent and express the condition. Prenatal and carrier testing are available in these situations.

Jim and Jill Kelly have recently set up a fund to help further research on Krabbe disease. The fund is called "Hunter's Hope" in honor of their son Hunter, who was recently diagnosed with Krabbe disease. For more information, please contact: Hunter's Hope Foundation, PO Box 643, Orchard Park, NY 14127, Phone (716) 667-1200.