What is Schindler disease?
Schindler disease is a lysosomal storage disorder. There is low activity of the enzyme alpha-N-acetylgalactosaminidase, which results in the buildup of complex compounds.
There are multiple forms of this disease, and they vary depending on severity and age of onset. The exact incidence of this disease is unknown, as it is a very rare disease.
What are the symptoms of Schindler disease?
Symptoms vary depending on which form of the disease one has. Type I is the most severe with the earliest onset, Type II is mild and sees the onset during adulthood, and Type III falls between the two.
Symptoms of Type I begin between the first nine to twelve months of a child’s life. Children will then stop developing normally and lose the skills that they have acquired. They will also experience muscular weakness, diminished muscular tone, muscle spasms, slow and stiff movements, misalignment of the eyes, rapid eye movements, visual impairment, and shock-like spasms throughout the body.
Schindler disease Type II sees symptoms like small, reddish skin lesions, swelling in the lower extremities, thickening of the horny layer of the skin, mild intellectual development, and distinctive, coarse facial features. Less common effects are hearing loss, vertigo, muscle weakness, ringing in the ears, and pain crises.
What causes Schindler disease?
Mutations in the NAGA genes result in this condition. This gene is responsible for the instructions for the enzyme alpha-N-acetylgalactosaminidase, and the mutations result in a low production. Without this enzyme, complex compounds build up and cause the characteristic symptoms. This gene is inherited in an autosomal recessive pattern.
How is Schindler disease diagnosed?
In terms of the first form of Schindler disease, it is typically diagnosed soon after birth. Doctors will look for characteristic symptoms and examine family history. Urinary tests, biopsies, and advanced imaging tests are used to diagnose all forms of this disease.
If one has a family history of Schindler disease, doctors recommend prenatal testing.
What are the treatments for Schindler disease?
There is no specific treatment for this condition; treatment is symptomatic. Investigational therapies are being studied currently.