PSAP
Chr 10ADARprosaposin
Also known as: GLBA, PARK24, PSAPD, SAP1, SAP2
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. [provided by RefSeq, Feb 2016]
Definitive — sufficient evidence for diagnostic panels
4 total gene-disease associations curated
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly LoF-intolerant (top ~10% of genes)
Tolerant to missense variation
This gene — mechanism propensity
Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.
The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.
ClinVar Variant Classifications
1008 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 31 | 7 | 4 | 0 | 42 |
Likely Pathogenic | 43 | 13 | 3 | 1 | 60 |
VUS | 1 | 253 | 36 | 10 | 300 |
Likely Benign | 0 | 8 | 231 | 248 | 487 |
Benign | 0 | 1 | 46 | 2 | 49 |
Conflicting | — | 47 | |||
| Total | 75 | 282 | 320 | 261 | 985 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →13 pathogenic / likely-pathogenic (of 20) ClinVar copy-number / structural variants overlap PSAP — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →
Protein Context — Lollipop Plot
PSAP · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
Host Response to Infection by Direct Analysis of Leukocyte Single Cell-type Gene Expression/transcript Abundance, Direct LS-TA
ACTIVE NOT RECRUITINGDetermine the Frequency of Variants in the GBA/PSAP Genes in Patients With MM or MGUS
RECRUITINGHost Response to Infection by Direct Analysis of Leukocyte Single Cell-type Gene Expression/transcript Abundance, Direct LS-TA. a Prospective Study Will Evaluate the Performance of Direct LS-TA in Triage Febrile Patients Into Major Categories of Infections: Viral, Bacterial or Active Tuberculosis.
NOT YET RECRUITINGExternal Resources
Links to major genomics databases and tools