ABOUT
What is Krabbe Disease ?
Symptoms
Some of the symptoms that may occur include:
- Feeding difficulties
- Irritability
- Stiffness of limbs
- Clenched fists
- Fever & seizures
There is progressive mental and motor deterioration, sometimes leading to deafness and blindness
Life expectancy of children with early infantile Krabbe disease is approximately 2 years.
A medical explanation
Krabbe disease is an inherited neurological condition with enlarged and characteristic globoid cells in the brain. A defect or mutation of the GALC gene results in a failure to make a special protein (an enzyme) required to breakdown and recycle complex lipids in the brain.
This enzyme is called 'galactoscerebrosidase'. When it fails to function, specific lipids accumulate and cause a breakdown of the myelin sheath that normally surrounds and protects nerve fibres. The breakdown of myelin leads to degeneration of the nervous system, especially the white matter, and therefore the disorder is referred to as a form of Leukodystrophy. The un-degraded complex lipids (galactocerebroside and psychosine) accumulate and are stored in special cellular bodies called lysosomes, and thus Krabbe disease is referred to as a lysosomal storage disorder.
Some 50 different inherited lysosomal storage disorders (LSDs) are known.
History of the disease
Krabbe (pronounced Krab-ay) disease (also called Krabbe or globoid cell leukodystrophy or galactosylceramide lipidosis) is a rare genetic disorder of the nervous system. The disease is named after Danish neurologist Knud Haraldsen Krabbe (1885-1965) who first recognised the disease.
The symptoms can appear soon after birth in the ‘Infantile’ form or in older children or adults in the 'Juvenile' or 'Late Onset' form. Most patients have the infantile form. Affected infants may not show symptoms at birth but soon develop signs of neurological damage.
The inheritance tree
Krabbe disease is caused by a deficiency of GALC ('galactoscerebrosidase') in the body. This is usually caused by a mutation of a gene called the GALC gene. The GALC gene is inherited from both parents, but Krabbe disease only arises when both parents pass on a faulty GALC gene, this is called an autosomal recessive pattern.
As such, although both parents each carry a copy of the mutated gene, they typically do not show any signs or symptoms of Krabbe disease. It also means that children with Krabbe disease can have siblings who do not inherit the condition.
Krabbe disease is very rare condition which means that statistically there is only one case in every 100,000 births. Approximately 1 in 150 people carries a faulty GALC gene.
