Krabbe disease is a disorder that affects the nervous system. It falls under a group of diseases called leukodystrophies, which harm the myelin sheath, a protective layer around nerve cells.
People with Krabbe disease lack an enzyme called galactocerebrosidase, which leads to the build-up of harmful substances in cells, causing brain cells to die and nerves to malfunction. There are two forms of Krabbe disease: infantile and late-onset. The infantile form affects 85 to 90% of those with Krabbe disease and shows symptoms in the first few months of life. Babies with infantile Krabbe disease become irritable, experience muscle weakness, fever, deafness, blindness, seizures, and slower mental and physical growth. Sadly, most infants with this form don’t live past the age of two. The late-onset form affects 10 to 15% of individuals and can appear between six months and 50 years of age. Symptoms include gradual vision loss, difficulty walking, stiff muscles, and mental decline. The severity of these symptoms varies, and the disease is often fatal 2 to 7 years after symptoms start. For infants who haven’t shown symptoms yet, treatment with umbilical-cord blood stem cells can slow down neural deterioration and reduce symptoms. This procedure works best when done shortly after birth. It’s also possible to use bone-marrow stem cells, but cord blood stem cells are less specific and cause fewer immune complications. For those who have already started showing symptoms, there is no cure.
Krabbe disease is caused by pathogenic (disease-causing) variants in the GALC gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a 1 in 532 chance to be a carrier.
Other names for this condition are diffuse globoid body sclerosis, galactosylceramidase deficiency disease, galactosylceramide lipidosis, galactosylsphingosine lipidosis, and psychosine lipidosis.