Krabbe Disease

Krabbe disease is relatively unknown, despite the fact that it is a very serious and often fatal condition. Anyone who is expecting a baby should be aware of Krabbe disease and its signs and symptoms. Like many other genetic disorders, there is no cure for Krabbe disease, though if caught early, it is sometimes possible to extend the lifespan of a child with the disorder.

What is Krabbe Disease?
Krabbe disease is a very rare, degenerative disorder that affects both the central and peripheral nervous system. A genetic disorder, Krabbe disease is classified as a Leukodystrophy disorder, which is caused by specific genetic mutations. Sometimes referred to as globoid cell leukodystrophy, Krabbe disease affects only a small number of people worldwide. In North America, about 1 in 100,000 to 200,000 children will get the disease.

What Causes Krabbe Disease?
Krabbe disease is the result of a gene mutation that is passed down from parent to child. Specifically, the galactosylceramidase (GALC) gene becomes abnormal, causing damage to the nervous system. The GALC gene is responsible for producing and maintaining the delicate coverings, called myelin, which protect our nerves. However, because of the gene mutation, not enough GALC enzyme is produced to create these nerve coverings. As a result, nerves in the brain become damaged, resulting in a host of severe symptoms.

How is Krabbe Disease Passed?
Krabbe disease is passed on from parent to child during conception. Each parent has a copy of the GALC gene, which is then passed along to baby. Some parents carry an abnormal version of this gene, even though they don�t manifest any symptoms of Krabbe disease. When both parents carry this genetic mutation, there is a 25% that their child will develop Krabbe disease.

Who Gets Krabbe Disease?
Krabbe disease usually affects infants, though it can appear in older children and even adults. Krabbe disease symptoms tend to be more severe in younger children. Subtypes of Krabbe disease are categorized according to the age when you first display symptoms.

 

• Type 1: Infantile Krabbe disease (onsets between 3 months and 6 months)
• Type 2: Late Infantile Krabbe disease (onsets between 6 months and 3 years)
• Type 3: Juvenile Krabbe disease (onsets between 3 years and 8 years)
• Type 4: Adult Krabbe disease (onsets after 8 years)

 

Infantile Krabbe disease is by far the most common, accounting for 85% of all known cases.

Symptoms of Krabbe Disease
Krabbe disease symptoms do not always appear right away. A baby can be born healthy and progress normally when, all of sudden, symptoms will begin to appear. Symptoms usually progress in stages:

Stage 1:
During stage 1, symptoms include:

 

• irritability
• unexplained crying
• trouble feeding
• stiffness of the muscles

 

Stage 2:
Stage 2 symptoms include:

 

• loss of muscle strength
• continued muscle stiffness
• arching of the back
• muscle spasms
• epileptic seizures
• vision problems

 

Stage 3:
Stage 3 Krabbe symptoms generally signal the complete degeneration of mental and motor skills. They include:

 

• inability to move
• rigid posture
• difficulty chewing, breathing, and swallowing
• mental incapacity
• blindness
• deafness

 

Prognosis
Krabbe disease is not associated with a very good prognosis. Most infants with Krabbe disease are expected to live for about two years. However, many children with the disease have lived longer, some up to the age of 8. Those who developed Krabbe disease in late childhood or adulthood have a much better prognosis, as symptoms tend to be milder.

Treatment
Unfortunately there is no cure for Krabbe disease, but there are a few promising treatments on the horizon. Some children who have received cord blood transplants from unrelated donors have shown remarkable improvements in symptoms. They have also lived much longer than expected. Bone marrow transplants also seem to slow down and even reverse some of the symptoms of Krabbe disease. For these treatments to be effective, they must take place before overt symptoms begin to manifest.

Other treatments for Krabbe disease focus on increasing the comfort of your child and helping him to increase his movement capabilities. Physical therapy that involves stretching and using the muscles helps children with Krabbe maintain their mobility for as long as possible.

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