Krabbe disease is a rare genetic disorder of the nervous system. It is a type of leukodystrophy.
Causes of Krabbe disease
A defect in the GALC gene causes Krabbe disease. Persons with this gene defect do not make enough of a substance called galactocerebroside beta-galactosidase (galactosylceramidase).
The body needs this substance to make myelin, the material that surrounds and protects nerve fibers. Without it, myelin breaks down, brain cells die, and nerves in the brain and other body areas do not work properly.
Krabbe disease can develop at various ages:
- Early-onset Krabbe disease appears in the first months of life. Most children with this form of the disease die before they reach age 2.
- Late-onset Krabbe disease begins in late childhood or early adolescence.
Krabbe disease is inherited, which means it is passed down through families. If both parents carry the defective gene related to this condition, each of their children has a 25% chance of developing the disease. (See: Autosomal recessive pattern)
This condition is very rare. It is most common among people of Scandinavian descent.
Krabbe disease Symptoms
Early-onset Krabbe disease:
- Changing muscle tone from floppy to rigid (decerebrate posturing)
- Hearing loss that leads to deafness
- Failure to thrive
- Feeding difficulties
- Irritability and sensitivity to loud sounds
- Severe seizures (may begin at a very early age)
- Unexplained fevers
- Vision loss that leads to blindness
Late-onset Krabbe disease:
Vision problems may appear first, followed by walking difficulties and rigid muscles. Symptoms vary from person to person. Other symptoms may occur.
Tests and Exams
An exam of the retina in the eye may show damage to the optic nerve. There may be signs or deafness and abnormal posturing in the late stages of the disorder.
Tests that may be done include:
- Blood test to look for galactosylceramidase levels in white blood cells
- CSF total protein
- MRI of the head
- Nerve conduction velocity
- Testing for the GALC gene defect
Treatment of Krabbe disease
There is no specific treatment for Krabbe disease.
Some people have had a bone marrow transplant in the early stages of the disease, but this treatment has risks.
United Leukodystrophy Foundation -- www.ulf.org
The outcome is likely to be poor. On average, infants with early-onset cases die before age 2. People who develop the disease at a later age have survived into adulthood with nervous system disease.
This disease damages the central nervous system. It can cause:
- Severe problems with muscle tone
The disease is usually life-threatening.
When to Contact a Health Professional
Call your health care provider if your child develops symptoms of this disorder. Seizures, loss of consciousness, or abnormal posturing may be emergency symptoms.
Prevention of Krabbe disease
Genetic counseling is recommended for persons with a family history of Krabbe disease who are considering having children.
A blood test can be done to see if you carry the gene for Krabbe disease.
Vanier MT, Caillaud C. Disorders of sphingolipid metabolism and neuronal ceroid-lipofuscinoses. In: Saudubray JM, van den Berghe G, Walter JH, eds. Inborn Metabolic Diseases: Diagnosis and Treatment. 5th ed. New York, NY:Springer; 2012:chap 39.
|Review Date: 5/7/2013
Reviewed By: Chad Haldeman-Englert, MD, FACMG, Wake Forest School of Medicine, Department of Pediatrics, Section on Medical Genetics, Winston-Salem, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.