Salla disease

Salla disease
Other namesSialic acid storage disease or Finnish type sialuria
Sialic acid
SpecialtyNeurology, endocrinology
Symptomshepatosplenomegaly; hypotonia; failure to thrive; developmental delays; cognitive deficits; seizures; skeletal abnormalities; dysplasia; metaphyses; clubbed feet; abnormally short thigh bones; dysplasia; nystagmus; ataxia.
Usual onsetAffected infants appear normal at birth but may develop symptoms during the first year of life.
DurationLifelong
Causesmutations in the SLC17A5 gene
Diagnostic methodclinical evaluation and genetic testing
Prognosisvariable
Frequency<1 per 1,000,000 individuals

Salla disease (SD) or mild Free Sialic Acid Storage Disease (FSASD) is an autosomal recessive lysosomal storage disease characterized by early physical impairment and intellectual disability. Salla disease (also referred to as Finnish-type sialuria, OMIM#604369) was first reported as a lysosomal storage disorder in a family from northern Finland. Salla refers to the area where the affected family resided. It was first described in 1979, after Salla, a municipality in Finnish Lapland and is one of 40 Finnish heritage diseases. The term Salla disease is now used in the literature not only for FSASD cases with the Finnish founder variant in SLC17A5, but also for any mild FSASD cases, independent of the mutation or region of origin.

FSASD (Salla and Infantile Free Sialic Acid Storage Disease) affects males and females in equal numbers. The worldwide prevalence of FSASD is estimated at less than 1 per 1,000,000 individuals. Higher estimated prevalence rates occur in the Salla region of Finland and other Scandinavian countries.