Salla disease

Salla disease, also called mild free sialic acid storage disease, is an autosomal recessive lysosomal storage disease whose main features are early physical impairment and intellectual disability. It takes its name from Salla, a municipality in Finnish Lapland, where it was first reported in a family from northern Finland, and it was first described in 1979. It is counted among the forty Finnish heritage diseases. The name is now used in the literature for any mild form of free sialic acid storage disease, not only the cases carrying the Finnish founder variant in the SLC17A5 gene and not only those from the original region. Males and females are affected in equal numbers. Worldwide prevalence is estimated at fewer than one in a million people, with higher estimated rates in the Salla region and other Scandinavian countries.