| Gene Symbol | COL4A2 |
| Function | COL4A2 encodes the alpha-2 chain of type IV collagen, a major structural component of basement membranes throughout the body. |
| Ensembl ID | ENSG00000134871 |
| GeneCards | COL4A2 |
| Human Protein Atlas | COL4A2 |
| Basement membrane integrity | The α1α1α2(IV) protomer (two COL4A1 chains + one COL4A2 chain) is the predominant collagen IV isoform in cerebrovascular basement membranes, providing structural integrity to blood vessels |
| Blood-brain barrier (BBB) maintenance | Collagen IV in the vascular basement membrane provides the structural scaffold for the BBB, supporting endothelial cells, pericytes, and astrocyte endfeet |
| Angiogenesis and vascular development | Required for proper cerebrovascular development; interacts with integrins and growth factor receptors on endothelial cells |
| Cell signaling scaffold | Collagen IV binds and presents growth factors (VEGF, PDGF, FGF) to cell surface receptors, modulating signaling |
| Neurovascular unit support | Maintains the structural relationship between neurons, glia, and blood vessels essential for neurovascular coupling and cerebral autoregulation |
| Clinical spectrum | Ranges from severe neonatal porencephaly to adult-onset lacunar strokes and leukoaraiencephalopathy |
| Vascular pathology | Thickened, irregular basement membranes; fibrinoid necrosis; small vessel occlusion; microaneurysm formation |
| Overlap with [COL4A1](/genes/col4a1) | Since COL4A1 and COL4A2 form obligate heterotrimers, mutations in either gene cause overlapping phenotypes |
| Pathogenesis | Basement membrane fragility leads to cerebrovascular rupture during fetal development or the perinatal period |
| Features | Fluid-filled cystic cavities in the brain parenchyma communicating with the ventricular system |
| Associated Diseases | neurodegeneration |
| Databases | GeneCardsUniProtNCBI GeneHPASTRING |