This is an old revision of this page, as edited by Fram (talk | contribs) at 15:21, 7 January 2025 (Fram moved page Draf/Combined Saposin Deficiency to Draft:Combined Saposin Deficiency without leaving a redirect: Wrong namespace). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 15:21, 7 January 2025 by Fram (talk | contribs) (Fram moved page Draf/Combined Saposin Deficiency to Draft:Combined Saposin Deficiency without leaving a redirect: Wrong namespace)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)Combined Saposin Defiency is a very rare metabolic and genetic disorder that is caused by the mutation in a gene PSAP. This disease belongs to Lysosomal Storage Diseases(LSDs). Because of complete saposin deficiency, it can cause clinical features of 4 diseases(Gaucher’s Disease, Metachromatic Leukodystrophy, Farber’s Disease, Krabbe’s Disease) to be apparent.
Medical condition| Combined Saposin Deficiency | |
|---|---|
| Other names | Prosaposin Defiency, Combined Sap Deficiency, PSAPD |
 | |
| PSAPD is inherited in a Autosomal Recessive fashion | |
Cause
PSAPD is caused by mutations in a PSAP gene, which is located on the long arm of chromosome 10 (10q22.1).
Symptoms
The symptoms of this disease are (according to OMIM): Respiratory failure, Hepatosplenomegaly, Poor feeding, Myoclonus, Hyperkinetic movements, Clonic seizures, Hypotonia, Leukodystrophy.
Also Optic atrophy was identified only in 1 patient.
Pathophysiology
It’s known that Prosaposin is a precursor of 4 proteins (Saposin A; B; C; D) and Saposin is a cofactor for many lysosomal sphingolipid metabolising enzymes, Saposin A is needed to stimulate galactocerebroside hydrolysis, Saposin B is needed to stimulate sulphatide hydrolysis and Saposin C is needed for glucocerebroside hydrolysis stimulation, Saposin D function is to stimulate ceramide hydrolysis.
According to one study, Prosaposin might be secreted extracellularly and bind some G protein-coupled receptors to exhibit neuroprotective effects.
In conclusion, PSAPD might not only cause accumulation of some sphingolipids, but also it can cause neuronal survival crisis.
Prevalence
The prevalence of this is unknown. Only 10 cases had been reported.
Treatment
This disease doesn’t have a cure, only symptomatic management is available
Reference
- ^ "Entry - #611721 - COMBINED SAPOSIN DEFICIENCY; PSAPD - OMIM". omim.org. Retrieved 2025-01-07.
{{cite web}}: line feed character in|title=at position 6 (help) - Hulková, H.; Cervenková, M.; Ledvinová, J.; Tochácková, M.; Hrebícek, M.; Poupetová, H.; Befekadu, A.; Berná, L.; Paton, B.C.; Harzer, K.; Böör, A.; Smíd, F.; Elleder, M. (2001-04-15). "A novel mutation in the coding region of the prosaposin gene leads to a complete deficiency of prosaposin and saposins, and is associated with a complex sphingolipidosis dominated by lactosylceramide accumulation". Human Molecular Genetics. 10 (9): 927–940. doi:10.1093/hmg/10.9.927. ISSN 0964-6906.
- ^ Bhat, Vivek; Thergaonkar, R. W.; Thakur, Manisha; Rajkamal, T. (2023-03-01). "Combined saposin deficiency: A rare occurrence". Medical Journal Armed Forces India. 79 (2): 238–240. doi:10.1016/j.mjafi.2021.01.024. ISSN 0377-1237.
- ^ "Clinical Synopsis - #611721 - COMBINED SAPOSIN DEFICIENCY; PSAPD - OMIM". omim.org. Retrieved 2025-01-07.
- "Wayback Machine". www.jlr.org. Archived from the original on 2023-04-28. Retrieved 2025-01-07.
- Gebai, Ahmad; Gorelik, Alexei; Nagar, Bhushan (2018-11-01). "Crystal structure of saposin D in an open conformation". Journal of Structural Biology. 204 (2): 145–150. doi:10.1016/j.jsb.2018.07.011. ISSN 1047-8477.
- Meyer, Rebecca C.; Giddens, Michelle M.; Coleman, Brilee M.; Hall, Randy A. (2014-10-17). "The protective role of prosaposin and its receptors in the nervous system". Brain Research. 1585: 1–12. doi:10.1016/j.brainres.2014.08.022. ISSN 0006-8993.
- ^ "Orphanet: Encephalopathy due to prosaposin deficiency". www.orpha.net. Retrieved 2025-01-07.