PIGM
Phosphatidylinositol Glycan Anchor Biosynthesis Class M
Gene Information Card
| Symbol | PIGM |
|---|---|
| Full Name | Phosphatidylinositol Glycan Anchor Biosynthesis Class M |
| Gene Type | Protein coding |
| Chromosomal Location | 1q23.2 |
| NCBI Gene ID | 93183 ncbi.nlm.nih.gov/gene/93183 |
| Ensembl ID | ENSG00000143190 |
| UniProt ID | Q9H3S5 |
| OMIM ID | 610273 |
| HGNC ID | 18758 |
| Aliases | GPI-M, PIG-M, MGC26594 |
Description
The PIGM gene encodes the mannosyltransferase enzyme that catalyzes the first mannose addition to the glycosylphosphatidylinositol (GPI) anchor precursor. This step is essential for GPI anchor biosynthesis, which tethers proteins to the cell surface. Mutations in PIGM cause inherited GPI deficiency (IGD) with thrombotic episodes and seizures.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Inherited GPI deficiency (IGD) | Loss-of-function mutations in PIGM impair mannosylation of the GPI anchor, reducing cell surface expression of GPI-anchored proteins such as CD55 and CD59, leading to complement dysregulation and thrombosis. | OMIM #610293; ClinVar; PMID: 17033974 |
| Thrombosis (associated with IGD) | Deficiency of GPI-anchored complement regulators (CD55, CD59) on platelets and endothelium predisposes to microvascular thrombosis. | OMIM #610293; PMID: 17033974 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Lung | 8.3 | Low |
| Liver | 6.1 | Low |
| Kidney | 9.7 | Low |
| Testis | 15.2 | Medium |
| Placenta | 11.4 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 14.0 | Moderate expression |
| K562 | 8.5 | Low expression |
| HepG2 | 6.3 | Low expression |
| SH-SY5Y | 11.2 | Moderate expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.270C>G (p.Cys90Trp) | Missense | Rare (found in IGD families) | Loss of mannosyltransferase activity; reduced GPI anchor synthesis |
| c.1A>G (p.Met1Val) | Start loss | Rare | Complete loss of protein expression; severe IGD phenotype |
Mutation functional classification
Loss of Function (LOF)
Missense and start-loss mutations in PIGM abolish or severely reduce mannosyltransferase activity, leading to GPI anchor deficiency.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
Not described; IGD is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • glycosylphosphatidylinositol mannosyltransferase activity (GO:0000506) | • attachment of GPI anchor to protein (GO:0016255) |
| • GPI anchor biosynthetic process (GO:0006506) | • membrane (GO:0016020) |
Pathways
• Glycosylphosphatidylinositol (GPI)-anchor biosynthesis (KEGG: hsa00563)
• GPI anchor biosynthesis (Reactome: R-HSA-162710)
Protein Summary
PIGM encodes a 423-amino acid transmembrane protein localized to the endoplasmic reticulum. It functions as a mannosyltransferase that transfers the first mannose from dolichol-phosphate-mannose to the GPI anchor precursor. This enzyme is critical for the biosynthesis of GPI anchors, which attach proteins such as CD55, CD59, and alkaline phosphatase to the cell membrane. Deficiency leads to inherited GPI deficiency (IGD), characterized by thrombosis, seizures, and intellectual disability.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PIGM Knockout HEK293 Cell Line | EDJ-KQ11189 | Human | 93183 | Details Get a Quote |
| PIGM Knockout A-549 Cell Line | EDJ-KQ39235 | Human | 93183 | Details Get a Quote |
| PIGM Knockout HCT 116 Cell Line | EDJ-KQ39236 | Human | 93183 | Details Get a Quote |
| PIGM Knockout HeLa Cell Line | EDJ-KQ39237 | Human | 93183 | Details Get a Quote |
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