What is Krabbe Disease?
Krabbe disease is a rare and usually deadly disorder of the
nervous system. It is an inherited genetic disease, which means that it is
passed down in families. People with Krabbe disease are not able to create
enough of a substance called galactosylceramidase, which is needed to make
myelin. Myelin is a material your body uses to surround and protect nerve
fibers. Without this protection, cells in the brain will die, and the nerves in
the brain and other parts of the body will not work properly.
Krabbe disease is seen mostly in infants (onset by age 6 months),
but it can also develop later in life. Unfortunately, there is currently no
cure for Krabbe disease, and most infants with this disease will die before age
What Are the Symptoms of Krabbe Disease?
In general, the younger the age of onset of Krabbe disease, the
faster the disease will progress. People who develop Krabbe disease later in
life may have less severe symptoms than infants who get the disease.
Early-Onset Krabbe Disease
Symptoms of early-onset Krabbe disease include:
- feeding problems
- persistent vomiting
- loss of head control
- irritability and excessive crying
- poor coordination of movement or stiffness
- muscle spasms (especially arms and legs)
- changes in muscle tone
- deterioration of mental and motor function
- deafness and blindness
Late-Onset Krabbe Disease
Symptoms of late-onset Krabbe disease in older children and
- progressive loss of vision leading to blindness
- difficulty walking (ataxia)
- poor hand coordination skills
- muscle weakness or rigid muscles
What Causes Krabbe Disease?
Krabbe disease is a genetic disorder, which means that a person
inherits the disease from their parents. It is caused by a genetic mutation — a
permanent change in the DNA sequence that makes up a certain gene. The mutation
affects the message that the gene sends to the cells in your body.
The gene for Krabbe disease can be found on chromosome 14. A
child needs to get an abnormal gene from both parents to inherit the disease.
The abnormal gene results in a shortage of an important enzyme that your body
needs called galactosylceramidase (GALC).
Your body needs GALC to make and maintain myelin, a substance
that surrounds and helps protect your nerves. In people with Krabbe disease,
who do not have GALC, a substance called galactolipids will build up in the
brain. Galactolipids are stored by cells called globoid cells. For this reason,
Krabbe disease is sometimes also called globoid cell leukodystrophy. There are
two types of Krabbe disease:
Krabbe disease occurs in the first months after birth, typically
before an infant reaches 6 months of age.
Krabbe disease occurs later in childhood or in early adolescence.
Who Is at Risk for Krabbe Disease?
Krabbe disease is very rare. According to the Mayo Clinic, the
disease affects about 1 in every 100,000 people in the United States. It occurs
most frequently in people of Scandinavian descent. A child has a one in four
chance of developing the disorder if both parents have the defective gene.
How Is Krabbe Disease Diagnosed?
Your doctor will conduct a physical exam to look for symptoms.
The doctor will take a sample of blood or skin tissue biopsy, and send it to a
laboratory for analysis. The laboratory can test for GALC enzyme activity in
the sample. If GALC activity levels are very low, the child may have Krabbe
disease. The following tests may also be performed to confirm a diagnosis:
scans (MRI) of the brain to look for abnormalities
conduction studies to measure the speed at which electrical
impulses are sent through the nervous system
examination to look for signs of damage to the optic nerve
testing to detect the genetic defect that causes Krabbe disease.
How Is Krabbe Disease Treated?
There is no cure for Krabbe disease. However, the following
treatments may be given to patients to help alleviate their symptoms:
- anticonvulsant medication to stop seizures
- muscle relaxer drugs (to help ease muscle spasms)
- physical therapy to help slow deterioration of
- occupational therapy to help older children with
common tasks, such as getting dressed and eating
Research has found two procedures that may have an effect on the
progression of Krabbe disease, rather than just treating the symptoms: bone
marrow transplantation (also called hematopoietic stem cell transplantation)
and cord blood transplantation. During these procedures, a person with Krabbe
disease receives cells from a healthy person. The new cells are able to make
the GALC enzyme that the patient could not make on his or her own. Both of
these procedures have risks of their own.
Bone Marrow Transplantation
An adult will donate some bone marrow (a material found in bones)
to replace the bone marrow in the child who has Krabbe disease. The best
results have been only in patients with late-onset Krabbe disease who have been
treated before severe symptoms develop. It has not been helpful in infants with
early-onset Krabbe disease who have already developed symptoms.
Cord Blood Transfusion
A doctor will transfuse cord blood stem cells into the patient.
The cells are obtained from the umbilical cord of a donor who is not related to
the patient. However, this procedure has also been shown to help only those
patients treated before symptoms appear.
What Are the Complications of Krabbe Disease?
The disease is usually life threatening. Since it damages a
person’s central nervous system, complications include:
- severe loss of muscle tone
- severe mental deterioration
- respiratory failure and death
What Is the Long-Term Outlook for People
With Krabbe Disease?
The outlook is very poor. On average, infants who develop Krabbe
disease will die before age 2. Children who develop the disease later in life
will live a bit longer, but typically die between 2 and 7 years after they are
How Can Krabbe Disease Be Prevented?
If both parents carry the genetic defect that causes Krabbe
disease, there is a 25 percent chance of passing the disease to their child.
The 25 percent risk of passing on the disease cannot be lowered if parents both
carry the genetic mutation. The only way to avoid the risk is if the carriers
decide to not have children. The parents can, however, find out if they carry
the gene for Krabbe disease through a blood test. If there is a family history
of Krabbe disease, prenatal tests can be done to screen the fetus for the
condition. Genetic counseling is recommended for people with a family history
of Krabbe disease if they are considering having children.