Infantile free sialic acid storage disease

Free sialic acid storage diseases are inherited conditions that lead to progressive neurological damage. There are three forms of free sialic acid storage diseases; an infantile form, an intermediate severe form and Salla disease. The infantile form is the most severe, with symptoms appearing before birth or soon after. Salla disease is the least severe with symptoms that start in the first year of life and progress slowly through adulthood. The intermediate severe form is less severe than the infantile form, but more severe than Salla disease.

General symptoms of free sialic acid storage diseases include developmental delay, low muscle tone, abnormal movements, and seizures. They are progressive, and symptoms get worse over time. All forms of free sialic acid storage disease are caused by genetic changes (mutations) in the SLC17A5 gene and are inherited in an autosomal recessive manner. Free sialic acid storage disease can be diagnosed by laboratory tests looking for sialic acid in the urine, imaging studies of the brain, and genetic testing. Treatment is based on the symptoms and maintaining quality of life. People with the least severe form of this disease (Salla disease) can live into adulthood.