Salla disease, also known as Finnish type sialuria, is a rare autosomal recessive disease that primarily affects the central nervous system. It is considered the mildest form of free sialic acid storage disorder.
Neurological symptoms related to this rare disease are usually seen in the first months of life. The first symptoms are muscular hypotonia, ataxia and delayed motor development. Nystagmus and epilepsy can also be seen. It eventually leads to significant intellectual disability. Patients may develop emphysema which is hypothesized to be due to abnormal inhibitory function of trypsin.
Salla disease is caused by mutations in the SLC17A5 gene 3. Mutations in the same gene also lead to infantile sialic acid storage disease, the most severe form of free sialic acid storage disorder.
Hypomyelination (including the U-fibers) with global cerebral volume loss is usually seen 4.
History and etymology
It was first described by Pertti Aula et al. in 1979 and named after Salla, a small municipality of Finland 5.
Treatment and prognosis
There is no specific treatment. It mainly consists of supportive care. There is only a mild reduction in life expectancy 3.
- 1. Barmherzig R, Bullivant G, Cordeiro D, Sinasac DS, Blaser S, Mercimek-Mahmutoglu S. A New Patient With Intermediate Severe Salla Disease With Hypomyelination: A Literature Review for Salla Disease. (2017) Pediatric neurology. 74: 87-91.e2. doi:10.1016/j.pediatrneurol.2017.05.022 - Pubmed
- 2. Pirkko Sonninen, Taina Autti, Tarja Varho, Mirja Hämäläinen, Raili Raininko. Brain Involvement in Salla Disease. (1999) American Journal of Neuroradiology. 20 (3): 433. Pubmed
- 3. Liisa E. Paavola, Anne M. Remes, Marika J. Harila, Tarja T. Varho, Tapio T. Korhonen, Kari Majamaa. A 13-year follow-up of Finnish patients with Salla disease. (2015) Journal of Neurodevelopmental Disorders. 7 (1): 20. doi:10.1186/s11689-015-9116-7 - Pubmed
- 4. Strauss KA, Puffenberger EG, Craig DW, Panganiban CB, Lee AM, Hu-Lince D, Stephan DA, Morton DH. Genome-wide SNP arrays as a diagnostic tool: clinical description, genetic mapping, and molecular characterization of Salla disease in an Old Order Mennonite population. (2005) American journal of medical genetics. Part A. 138A (3): 262-7. doi:10.1002/ajmg.a.30961 - Pubmed
- 5. Aula P, Autio S, Raivio KO, Rapola J, Thodén CJ, Koskela SL, Yamashina I. "Salla disease": a new lysosomal storage disorder. (1979) Archives of neurology. 36 (2): 88-94. Pubmed