Combined SAP deficiency is a fatal infantile lysosomal storage disorder with hepatosplenomegaly and severe neurological disease. It is caused by mutations in the PSAP gene leading to absence or non-functionality of the prosaposin protein. Mammalian prosaposin encodes in tandem four small acidic activator proteins (saposins) with specificities for glycosphingolipids hydrolases.
Category
Congenital disorder of metabolism; Lysosomal storage disease
Brite
Human diseases [BR:br08402]
Congenital disorders of metabolism
Lysosomal storage diseases
H01239 Combined SAP deficiency
Human diseases in ICD-11 classification [BR:br08403]
05 Endocrine, nutritional or metabolic diseases
Metabolic disorders
Inborn errors of metabolism
5C56 Lysosomal diseases
H01239 Combined SAP deficiency
Defects in PSAP saposin-B region are the cause of metachromatic leukodystrophy [DS:H00127]. Defects in PSAP saposin-C region are the cause of atypical Gaucher disease [DS:H00126]. Defects in PSAP saposin-A region are the cause of atypical Krabbe disease [DS:H00135].
Hulkova H, Cervenkova M, Ledvinova J, Tochackova M, Hrebicek M, Poupetova H, Befekadu A, Berna L, Paton BC, Harzer K, Boor A, Smid F, Elleder M
Title
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.
Sun Y, Witte DP, Zamzow M, Ran H, Quinn B, Matsuda J, Grabowski GA
Title
Combined saposin C and D deficiencies in mice lead to a neuronopathic phenotype, glucosylceramide and alpha-hydroxy ceramide accumulation, and altered prosaposin trafficking.
