Krabbe Disease (Globoid Cell Leukodystrophy)

What is Krabbe disease?

Krabbe disease (also called globoid cell leukodystrophy) is a rare, inherited neurological condition. It’s pronounced “KRAH-buh.”

Krabbe disease is part of a group of disorders known as leukodystrophies, which result from the loss of myelin (demyelination) in your nervous system. A myelin sheath is a protective sleeve that’s wrapped around each nerve cell that ensures the rapid transmission of nerve signals.

The disease is also characterized by abnormal cells in your brain called globoid cells, which are large cells that usually have more than one nucleus.

The demyelination results in the destruction of brain cells, which causes progressive neurological issues, such as:

• Intellectual disability.
• Paralysis.
• Deafness.

Krabbe disease is a degenerative condition, meaning it progressively gets worse. It usually results in death.

The condition gets its name from the Danish neurologist Knud Krabbe.

Who does Krabbe disease affect?

Approximately 90% of Krabbe disease cases begin between 1 and 7 months of age. This is called the infantile form. The late-onset form of the condition occurs at 18 months or a later age, including adolescence and adulthood.

Krabbe disease is an inherited condition, meaning that biological parents pass it on to their child through their genes.

How common is Krabbe disease?

Krabbe disease is generally rare, but its frequency varies widely across the world. Researchers estimate that it occurs in 1 per 100,000 live births in Europe and about 1 per 250,000 live births in the United States.

A higher incidence, about 6 cases per 1,000 people, has been reported in a few isolated communities in Israel.

What are the symptoms of Krabbe disease?

The severity of the symptoms of Krabbe disease depends on the age the symptoms begin. The infantile form is rapidly progressive and usually fatal by age 2. Late-onset Krabbe disease has relatively milder symptoms and a longer life expectancy.

Signs and symptoms of infantile Krabbe disease

There are three general stages of symptoms in the infantile form of Krabbe disease, which include:

Stage 1: A baby with Krabbe disease generally grows and develops well until 4 to 6 months of age when the symptoms begin. They include:

• Restlessness.
• Irritability.
• Vomiting.
• Feeding difficulty.
• Failure to thrive.
• Episodes of fever without any sign of infection.
• Muscle weakness.

A baby with Krabbe disease may be hypersensitive to touch, noise or bright light and can develop tonic spasms in the presence of these triggers.

Stage 2: Symptoms of stage two include:

• Vision changes.
• Optic atrophy.
• Abnormal posture due to spastic contraction of the muscles of their neck, trunk and lower extremities that produces a severe backward arching from neck to heel (opisthotonic posturing).
• Seizure-like episodes.
• Slowed mental and physical development.
• Regression of previously acquired developmental milestones.

Stage 3: Symptoms of stage three include:

• Blindness.
• Deafness.
• Abnormal body posture that involves their arms and legs held straight out, their toes pointed downward and their head and neck arched backward (decerebrate posturing).
• Decreased mobility.

Signs and symptoms of late-onset Krabbe disease

Late infantile Krabbe disease begins between 13 and 36 months of age. The symptoms, listed in progressive order, include:

• Irritability.
• Vision changes.
• Abnormal gait (walking).
• Seizures.
• Periods of stopped breathing (apneic episodes).
• Body temperature instability.

The average age of mortality is six years.

The symptoms of juvenile-onset Krabbe disease include:

• Vision changes.
• Tremors.
• Gait abnormalities.
• Impaired control of voluntary movements and progressive rigidity of muscles.
• Attention-deficit/hyperactivity disorder (ADHD).

The rate of progression of this form of Krabbe disease varies widely, but the disease eventually results in death within 10 years of the diagnosis.

Late-onset Krabbe disease symptoms include:

• A burning sensation in arms and legs.
• Mood and behavior changes.
• Ataxia.
• Spasticity.
• Vision changes and blindness.
• Seizures.
• Hearing loss and deafness.

Most people with late-onset Krabbe disease deteriorate both mentally and physically.

What causes Krabbe disease?

Krabbe disease is a hereditary condition passed on to biological children through a gene. It’s inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of a person with an autosomal recessive condition each carry one copy of the mutated gene, but the parents typically don’t show signs and symptoms of the condition.

Krabbe disease is caused by mutations in a gene known as GALC, which results in a lack of an enzyme called galactocerebrosidase. Your body needs this enzyme for the metabolism of galactocerebroside, a component of myelin (the protective sheath around nerves).

Without this important enzyme, myelin sheaths break down (demyelination) throughout your central nervous system. This causes the neurological symptoms of Krabbe disease.

How is Krabbe disease diagnosed?

Many states in the U.S. include screening for Krabbe disease in a standard newborn screening protocol. The screening for Krabbe disease is a blood test.

The other main way to diagnose Krabbe disease is through imaging tests. An MRI (magnetic resonance imaging) scan can help show differences in your child’s brain that point to Krabbe disease. MRI is particularly useful in identifying brain lesions in Krabbe disease. These tests can also help diagnose the condition in the juvenile and adult forms.

If your child has been diagnosed with Krabbe disease, they’ll likely need a hearing assessment and an eye examination to determine the degree of hearing and vision loss. This can determine what type of hearing and vision aids they need.

If your child has been diagnosed with Krabbe disease, your provider will likely recommend genetic counseling and testing for you and your partner to assess the risk of having another child with the condition. They may also recommend testing to your biological family members to see if they’re carriers of the abnormal gene.

How is Krabbe disease treated?

Unfortunately, there’s no cure for Krabbe disease, and it usually results in death.

There’s one type of treatment that can slow the progression of Krabbe disease called hematopoietic stem cell transplant (HSCT).

A stem cell transplant helps your body replace unhealthy cells with healthy or normal cells. Hematopoietic cells are immature cells that can develop into all types of blood cells, including white blood cells, red blood cells and platelets.

With HSCT, the hematopoietic cells from a healthy donor are transplanted to a child with Krabbe disease. HSCT helps your child’s body populate their brain with healthy cells and good GALC enzyme activity. However, HSCT works best when given before the onset of symptoms.

Researchers are working on finding better treatment options for Krabbe disease. As there’s currently no cure for Krabbe disease and it gets worse over time, the main type of management is supportive care, which may include:

• Muscle relaxants for spasms.
• Anticonvulsant medications to help seizures.
• Physical therapy to increase mobility.
• Occupational therapy for older children and adults.
• Tube feedings for proper nutrition if swallowing is affected.

Can Krabbe disease be prevented?

As Krabbe disease is an inherited condition, there’s nothing you can do to prevent it.

If you’re concerned about the risk of passing on Krabbe disease or other genetic conditions before trying to have a biological child, talk to a healthcare provider about genetic counseling.

What is the prognosis for Krabbe disease?

The prognosis (outlook) for Krabbe disease is poor. It usually results in death, but life expectancy varies based on the age of onset.

The average lifespan for children with infantile Krabbe disease is 13 months. Most children with late infantile disease die within two years of the beginning of symptoms.

The progression of the condition and life expectancy vary in both juvenile-onset and adult-onset Krabbe disease.

Death from Krabbe disease usually results from respiratory failure due to poor muscle tone or infections from aspiration (when something enters your airway or lungs by accident).

When should my child with Krabbe disease see their healthcare provider?

Your child will need to see their healthcare team regularly to monitor their symptoms and the progression of the disease and to adjust their supportive care plan. If your child has any new symptoms, talk to their provider.

A note from Cleveland Clinic

Krabbe disease is a rare, inherited neurological condition. Learning that your child has Krabbe disease can be overwhelming. Know that you’re not alone — resources that offer support and education are available to help you and your family. It’s important that your child has a team of healthcare providers who are familiar with the disease so that they can receive the best care.