Entrez ID	Official symbol	Synonyms	Description	Location	Type of protein	External annotation
5660	PSAP	GLBA, SAP1, SAP2	prosaposin	10q22.1	protein-coding	Genecard

uniprot_summary

refseq_summary

Saposin-A and saposin-C stimulate the hydrolysis of glucosylceramide by beta-glucosylceramidase (EC 3.2.1.45) and galactosylceramide by beta-galactosylceramidase (EC 3.2.1.46). Saposin-C apparently acts by combining with the enzyme and acidic lipid to form an activated complex, rather than by solubilizing the substrate.|Saposin-B stimulates the hydrolysis of galacto-cerebroside sulfate by arylsulfatase A (EC 3.1.6.8), GM1 gangliosides by beta-galactosidase (EC 3.2.1.23) and globotriaosylceramide by alpha-galactosidase A (EC 3.2.1.22). Saposin-B forms a solubilizing complex with the substrates of the sphingolipid hydrolases.|Saposin-D is a specific sphingomyelin phosphodiesterase activator (EC 3.1.4.12).|Prosaposin: Behaves as a myelinotrophic and neurotrophic factor, these effects are mediated by its G-protein-coupled receptors, GPR37 and GPR37L1, undergoing ligand-mediated internalization followed by ERK phosphorylation signaling.|Saposins are specific low-molecular mass non-enzymic proteins, they participate in the lysosomal degradation of sphingolipids, which takes place by the sequential action of specific hydrolases.

This gene encodes a highly conserved preproprotein that is proteolytically processed to generate four main cleavage products including saposins A, B, C, and D. Each domain of the precursor protein is approximately 80 amino acid residues long with nearly identical placement of cysteine residues and glycosylation sites. Saposins A-D localize primarily to the lysosomal compartment where they facilitate the catabolism of glycosphingolipids with short oligosaccharide groups. The precursor protein exists both as a secretory protein and as an integral membrane protein and has neurotrophic activities. Mutations in this gene have been associated with Gaucher disease and metachromatic leukodystrophy. Alternative splicing results in multiple transcript variants, at least one of which encodes an isoform that is proteolytically processed.

Caregory	Description	Value	Value range ( Low - High )	Comment
PLI	The probability of being loss-of-function (LoF) intolerant	0.95	[0, ..., 1]	Genes with high pLI scores (pLI ≥ 0.9) are extremely LoF intolerant, whereby genes with low pLI scores (pLI ≤ 0.1) are LoF tolerant. The score is calculated based on high-quality exome sequence data (ExAC) for 60,706 individuals of diverse ethnicities.
Haploinsufficiency (HI) score rank	Predicted probability of exhibiting haploinsufficiency		[100, ..., 1]	High ranks (e.g. 0-10%) indicate a gene is more likely to exhibit haploinsufficiency, low ranks (e.g. 90-100%) indicate a gene is more likely to NOT exhibit haploinsufficiency (DECIPHER, PMID: 20976243). haploinsufficiency means a single functional copy of a gene is insufficient to maintain its normal function and is extremely intolerant of LoF variation.
Gene brain expressed	Queried gene is expressed in brain tissues	True	[False, True]	The gene expression data are extracted from GTEx v7 and BrainSpan. A gene with the expression value of (log 2 based (TPM+1)) at least 1 TPM/RPKM/FPKM in one or more tissues related to the brain is considered brain-expressed.
Protein brain expressed	Queried protein is expressed in brain tissues	True	[False, True]	The protein expression data are extracted from ProteomicsDB (v2018.09). A protein with the expression value of (log based 10 (iBAQ intensity)) at least 0.5 in one or more tissues related to the brain is considered brain-expressed protein.
Carrying LoF DNMs	Number of loss-of-function DNMs hit the queried gene	0 (Case)	[0, ..., 67] with average of 0.160	Loss of function (LoF) mutations include frameshift indels, nonsense (stop-gained) and splice-site mutations, which can result in the gene product having less or no function and can have deleterious consequences.
		0 (Control)	[0, ..., 6] with average of 0.044
Carrying missense DNMs	Number of missense DNMs hit the queried gene	3 (Case)	[0, ..., 55] with average of 0.846	Missense mutations can result in changes in protein sequences, but are commonly considered to have less deleterious impacts than LoF mutations.
		0 (Control)	[0, ..., 21] with average of 0.300
FMRP binding targets	FMRP inteacting parters	True	[False, True]	FMRP loss of function causes Fragile X syndrome (FXS). The binding targets identified crosslinking immunoprecipitation (HITS-CLIP) in mouse brains (PMID:21784246). Many FMRP targets are among genes implicated in different neuropsychiatric diseases, such as autism, schizophrenia.
Postsynaptic density (PSD)	Protein associates with postsynaptic membranes of excitatory synapses	False	[False, True]	Abnormalities with PSD proteins are linked to various neuropsychiatric diseases including neurodevelopmental disorders.
Human essential genes	-	False	[False, True]	Genes are thought to be critical for human survival.