Salla disease (or Finnish type sialuria) is a syndrome leading to early physical impairment and mental retardation. This is due to a mutation in chromosome 6 (a recessive allele in the gene SLC17A5 the locus of which is 6q14-15). more...
This gene codes for sialin, a lysosomal membrane protein that transports the charged sugar, N-acetylneuraminic acid (sialic acid), out of lysosomes. The mutation causes sialic acid to build up in the cells.
First described by P Aula et al. in 1979, Salla disease is named after Salla, a municipality in Finnish Lapland. It is one of nearly 40 diseases that make up the Finnish disease heritage. The majority of 100 Salla disease patients in Finland live in Salla or neighboring municipalities; there are maybe 30-40 patients living abroad, majority of them (one source says 27) in Sweden.
Individuals with Salla disease may present with nystagmus in the first months of life as well as hypotonia and cognitive impairment. The most severely impaired children do not ambulate or acquire language, but they do typically learn to walk and speak and have normal life expectancy. The MRI shows arrested or delayed myelination.
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