Salla disease (SD) is the mildest of the sialic storage diseases, which are inherited disorders characterized by progressive neurological problems. Infants with Salla disease appear normal at birth and then develop low muscle tone in the first year of life. As they grow, they exhibit developmental delay, movement and balance problems, and intellectual disability. Later they develop muscle stiffness, seizures, and involuntary movements of the limbs. Individuals with Salla disease usually survive into adulthood but may become nonverbal and unable to walk as they age. There is no cure for Salla disease; however medical surveillance and care may help to improve some symptoms and overall condition of life. Salla disease is caused by pathogenic variants in the SLC17A5 gene.