Krabbe disease is caused by a deficiency in a specific enzyme that helps break down a lipid (fat) that is found in the kidneys and the epithelial cells of both the colon and small intestine. This fat is also found in myelin, which is the protective layer that surrounds nerves.
Infants with this disease do not show any symptoms at birth. However, these begin to appear between the ages of six months and three and are severe. In babies, the disease is often fatal, with the infant not living beyond two years of age.
There is also adult-onset Krabbe disease which expresses similar symptoms, but the progression is slower, and the sufferer has a longer lifespan because of this. The incidents of Krabbe disease are thought to be between one in 100,000 to 200,000 births.
Symptoms of Krabbe disease are numerous, and if fats are allowed to build up around the myelin sheath, then this can compromise the health of the entire nervous system. As the growth of myelin itself is affected, various symptoms such as impaired motor skills and poor mental performance arise. Even brain cells can die, which is why mental health and mental agility are also affected.
Krabbe disease causes nerve demyelination which leads to significant physical and mental symptoms. This is similar to other diseases that cause demyelination in the body, such as multiple sclerosis. Physical activities, including walking, running, lifting, holding, and carrying, can all be affected by Krabbe disease.
With the infant onset of Krabbe disease, the symptoms of concern include seizures, vomiting, fever, difficulties in swallowing, limb weakness, muscle spasms, blindness, and impaired motor and mental development.
Krabbe disease, which is also known as globoid cell leukodystrophy, is characterised by the build-up of lipids in various cells and tissues. This causes the destruction of the nerve-protective myelin coating.
Essentially, Krabbe disease is caused by a genetic disorder involving the GALC gene. This genetic defect prevents galactocerebrosidase, an essential enzyme needed for fat metabolism, from being manufactured in the body to adequate levels. The consequence of this is the build-up of toxic substances, such as lipids, in body cells.
Despite this, adult-onset Krabbe disease is often much milder than the infant form, and symptoms are, therefore, much easier to manage, even though there is no known cure for this neurological disorder.
The risk factors behind the development of this genetic disease are if both parents of a child each carry one copy of the mutated genes without suffering from the condition themselves.
Blood testing for enzyme activity and genetic screening of the parents for the defective genes behind this disease is the most common medical diagnostics used to diagnose Krabbe disease.
Additionally, for those with the disease itself, MRI scans can also be performed as this helps to detect brain lesions and other damage caused by the disease internally. Hearing and vision testing also help medical professionals solve the puzzle of diagnosing this distressing condition in individuals so that treatment to improve quality of life, where possible, can begin.