Krabbe disease is a rare, inherited degenerative disorder of the central and peripheral nervous systems. It is characterized by the presence of globoid cells (cells that have more than one nucleus), the breakdown of the nerve’s protective myelin coating, and destruction of brain cells. Krabbe disease is one of a group of genetic disorders called the leukodystrophies. These disorders impair the growth or development of the myelin sheath, the fatty covering that acts as an insulator around nerve fibers, and cause severe degeneration of mental and motor skills. Myelin, which lends its color to the “white matter” of the brain, is a complex substance made up of at least 10 different enzymes. Each of the leukodystrophies affects one (and only one) of these substances. Krabbe disease is caused by a deficiency of galactocerebrosidase, an essential enzyme for myelin metabolism. The disease most often affects infants, with onset before age 6 months, but can occur in adolescence or adulthood. Symptoms include irritability, unexplained fever, limb stiffness, seizures, feeding difficulties, vomiting, and slowing of mental and motor development. Other symptoms include muscle weakness, spasticity, deafness, and blindness.
What is the prognosis?
Infantile Krabbé disease is generally fatal before age 2. Prognosis may be significantly better for children who receive umbilical cord blood stem cells prior to disease onset or early bone marrow transplantation. Persons with juvenile- or adult-onset cases of Krabbé disease generally have a milder course of the disease and live significantly longer.
Is there any treatment?
There is no cure for Krabbe disease. Results of a very small clinical trial of patients with infantile Krabbe disease found that children who received umbilical cord blood stem cells from unrelated donors prior to symptom onset developed with little neurological impairment. Results also showed that disease progression stabilized faster in patients who receive cord blood compared to those who receive adult bone marrow. Bone marrow transplantation has been shown to benefit mild cases early in the course of the disease. Generally, treatment for the disorder is symptomatic and supportive. Physical therapy may help maintain or increase muscle tone and circulation.
How common is Krabbe disease?
In the United States, Krabbe disease affects about 1 in 100,000 individuals. Approximately 2 million people (or one out of 125) in the United States are carriers of the genetic deficiency that causes Krabbe Disease. Yet, awareness about this disease is very limited. A higher incidence (6 cases per 1,000 people) has been reported in a few isolated communities in Israel.
How do people inherit Krabbe disease?
Krabbe disease is inherited in an autosomal recessive manner. If both parents carry a disease-causing mutation in the GALC gene there is a 25 percent chance of having a Krabbe affected child with each conception, a 50 percent chance that each offspring will be a carrier and a 25 percent chance of having a child who does not carry a disease causing mutation. This genetic disease is found in all ethnic groups. The carrier rate in the general population is estimated to be 1 in 125. Krabbe Disease occurs in about 1 in 100,000 births in the United States. Diagnosis can easily be made by testing the white cells from a blood sample for GALC activity.
Organizations
Hunter's Hope Foundation [A Leukodystrophy Resource]
P.O. Box 643
Orchard Park, NY 14127
info@huntershope.org
http://www.huntershope.org
Tel: 716-667-1200 877-984-HOPE (-4673)
Fax: 716-667-1212
United Leukodystrophy Foundation
2304 Highland Drive
Sycamore, IL 60178
office@ulf.org
http://www.ulf.org
Tel: 815-895-3211 800-728-5483
Fax: 815-895-2432
National Organization for Rare Disorders (NORD)
P.O. Box 1968
(55 Kenosia Avenue)
Danbury, CT 06813-1968
orphan@rarediseases.org
http://www.rarediseases.org
Tel: 203-744-0100 Voice Mail 800-999-NORD (6673)
Fax: 203-798-2291
Myelin Project
1400 Wallace Blvd.
Suite 258
Amarillo, TX 79106
candace.root@myelin.org
http://www.myelin.org
Tel: 806-356-4693 800-869-3546
Fax: 806-356-4694