Krabbe disease

Krabbe disease
Globoid cell leukodystrophy PAS.jpg
A histopathology slide of a brain with Krabbe disease showing giant cells with PAS stain inclusions ("globoid cells") within astrocytic gliosis and loss of myelinated fibers.
Synonyms	Globoid cell leukodystrophy Galactosylceramide lipidosis GALC deficiency Galactocerebrosidase deficiency
Symptoms	Infancy: Developmental delay, irritability, spasticity, hypotonia, microcephaly, optic atrophy Juvenile: Muscle weakness, vision loss, developmental regression Adult: Burning paresthesias in extremities, loss of manual dexterity, muscle weakness, sensory neuropathy, muscle atrophy
Complications	Severe neurological deterioration, paralysis, blindness, seizures, respiratory failure
Usual onset	Usually within 3 to 6 months of birth, but can present in childhood or adulthood
Duration	Progressive and degenerative
Types	Infantile, juvenile, and adult
Causes	Mutation of GALC gene
Risk factors	Parents who are heterozygous for a GALC mutation
Diagnosis	Histopathology, genetic testing, enzyme assay
Differential diagnosis	Metachromatic leukodystrophy, adrenoleukodystrophy, Pelizaeus-Merzbacher disease
Prevention	Prenatal diagnosis and screening of at-risk couples
Treatment	Primarily supportive care, symptomatic treatment, stem cell transplantation
Medication	No specific cure, palliative care is the mainstay
Prognosis	Poor in infantile onset; better outcomes with early hematopoietic stem cell transplantation
Frequency	Approximately 1 in 100,000 births
Deaths	High mortality rate, especially in early-onset forms

Krabbe disease (globoid cell leukodystrophy) is a rare, inherited lysosomal storage disorder affecting the central nervous system. It leads to progressive demyelination, causing severe neurological decline. The condition is caused by a mutation in the GALC gene, which results in a deficiency of the galactosylceramidase enzyme. This leads to the toxic accumulation of psychosine, damaging myelin-producing cells called oligodendrocytes.

The disease is named after Knud Krabbe, a Danish neurologist who first described the condition in 1916.

Signs and Symptoms

Symptoms vary based on the age of onset:

Krabbe Disease Symptoms by Age Group

Age of Onset	Symptoms
Infantile-onset (most common, before 12 months)	Irritability, hypotonia, spasticity, feeding difficulties, developmental regression, optic atrophy, seizures, paralysis, blindness
Juvenile-onset (1–10 years)	Muscle weakness, vision loss, behavioral changes, developmental regression, loss of motor skills, ataxia
Adult-onset (rare, after adolescence)	Burning paresthesias, muscle atrophy, sensory neuropathy, cognitive impairment, tremors, gait disturbances

Causes

Krabbe disease is caused by a mutation in the GALC gene, located on chromosome 14 (14q31). The condition is inherited in an autosomal recessive manner, meaning a child must inherit two copies of the mutated gene (one from each parent) to develop the disease.

The GALC enzyme deficiency leads to:

• Accumulation of galactosylceramide, leading to toxic effects on myelin-forming cells.
• Buildup of psychosine, which destroys oligodendrocytes, preventing proper myelin formation.
• Widespread demyelination, disrupting nerve signaling in the brain and spinal cord.

Diagnosis

Krabbe disease is diagnosed through:

• Newborn screening – Blood tests to measure GALC enzyme activity.
• Genetic testing – Identification of mutations in the GALC gene.
• MRI brain scan – Shows white matter abnormalities due to demyelination.
• Nerve conduction studies – Assess neurological impairment.
• Lumbar puncture (CSF analysis) – Elevated protein levels suggestive of leukodystrophy.
• Biopsy – Examining globoid cells in the nervous system.

Treatment

There is no cure for Krabbe disease. Treatment focuses on:

• Hematopoietic stem cell transplantation (HSCT) – If performed before symptoms appear, it may slow disease progression.
• Supportive care – Physical therapy, speech therapy, nutritional support.
• Seizure management – Anticonvulsants for epilepsy.
• Pain management – Muscle relaxants, analgesics.
• Feeding support – Gastrostomy tubes for feeding difficulties.
• Respiratory care – Assistance with breathing problems in advanced cases.

Prognosis

The prognosis depends on the age of onset:

• Infantile-onset – Severe and usually fatal by age 2.
• Juvenile-onset – Progresses more slowly, survival varies.
• Adult-onset – Milder but leads to progressive disability.

Epidemiology

Krabbe disease is rare, occurring in 1 in 100,000 births worldwide. However, its frequency varies by population:

• Higher rates in Scandinavian countries (1 in 50,000 births).
• Higher rates in the Druze population in Israel (6 in 1,000 births due to consanguinity).
• Extremely rare in Japan.

Society and Culture

The disease gained public attention through:

• Hunter Kelly, son of NFL quarterback Jim Kelly, who was diagnosed with Krabbe disease in 1997.
• Legislative efforts to include Krabbe disease in newborn screening programs in several U.S. states.

Krabbe Disease in Animals

Krabbe disease has been identified in:

• Dogs – Common in West Highland White Terriers and Cairn Terriers.
• Cats – Certain feline breeds.
• Monkeys and mice – Used for scientific research.

See Also

• Lysosomal storage diseases
• Leukodystrophy
• Genetic disorders
• Neurometabolic disorders
• Hematopoietic stem cell transplantation

External Links

• GeneReviews entry on Krabbe disease
• OMIM entries on Krabbe disease