Krabbe disease is one of many hundreds of inherited metabolic disorders. Named after the Danish neurologist Knud Krabbe, the disease causes progressive damage to the nervous system, eventually resulting in the death of the individual. The disease is common in newborns before they reach six months of age and treatment must start at the earliest. Most newborns affected by Krabbe disease do not reach the age of two.

Krabbe disease is caused due to genetic mutation on the 14th chromosome in an infant. A child needs to inherit two copies of the abnormal genome from both its parents, after which it has a 25 percent chance of inheriting both the recessive genes and developing the disease.

On inheriting the defective genome, the body doesnt produce enough of the enzyme galactosylceramidase (GALC). Galactosylceramidase is essential for breaking down unmetabolised lipids like glycosphingolipid and psychosine in the brain. These unmetabolised lipids are toxic to some of the non-neuron cells present in the brain.

Late-onset Krabbe disease, however, can be caused by a different genetic mutation which leads to a lack of a different enzyme, known as active saposin A.

Symptoms between early-onset and late-onset Krabbe disease differ slightly. Infants suffering from early-onset Krabbe disease suffer from symptoms like excessive irritability, difficulty swallowing, vomiting, unexplained fevers, and partial unconsciousness. Other common neuropathic symptoms include hypersensitivity to sound, muscle weakness, slowing of mental and motor development, spasticity, deafness, optic atrophy, optic nerve enlargement, blindness, and paralysis.

Late-onset Krabbe disease emerges with symptoms like the development of cross-eyes, slurred speech, slow development, and loss of motor functions.

The disease is diagnosed after a physician conducts a primary physical exam. A blood or skin tissue biopsy can test for GALC levels in the body and low levels can indicate the presence of Krabbe disease. Further testing through imaging scans (MRI), nerve conduction studies, eye examination, genetic testing and amniocentesis can also help diagnose the disease.

There is no cure for Krabbe disease. Treatment is mostly palliative in nature with a focus towards dealing with symptoms and providing supportive care. Experimental trials using hematopoietic stem cell transplant (HSCT), bone marrow transplantation, stem cell therapy, and gene therapy have seen some results in the small number of patients that they have been used on.

(Edited by : Shoma Bhattacharjee)

First Published:Jul 15, 2022, 06:32 AM IST

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Krabbe disease, which mostly affects newborns causes, symptoms, and treatment - CNBCTV18