Collagen type IV alpha 5 chain (COL4A5) (COL4A5)

The Collagen type IV alpha 5 chain (COL4A5) is a critical structural protein that forms the framework of the glomerular basement membrane (GBM) in the kidney. It assembles into a specialized alpha 3-alpha 4-alpha 5 heterotrimeric network, which is essential for the mechanical stability and selective permeability of the renal filtration barrier (UniProt P29400). Mutations in the COL4A5 gene, located on the X chromosome, lead to X-linked Alport syndrome, a condition characterized by progressive hematuria, proteinuria, and eventual renal failure (NCBI Gene 1287). Because the absence of this protein results in a compromised GBM, therapeutic efforts focus on preserving renal function and, more recently, restoring the protein's presence. While standard treatments like ACE inhibitors and ARBs aim to reduce glomerular pressure, experimental therapies such as antisense oligonucleotides and gene replacement are being developed to directly address the underlying genetic deficiency (PubMed PMID: 32673434). A significant challenge in treating COL4A5-related disorders is the risk of an immune response against the newly introduced protein, which can lead to anti-GBM nephritis in patients who previously lacked the protein entirely (PubMed PMID: 31113773).

Other names

Collagen alpha-5(IV) chainASLNATSCOL4A5Alport syndrome locus

Reduction of glomerular capillary pressure and proteinuria via RAAS inhibition; experimental restoration of protein function through gene therapy, exon skipping, or antisense oligonucleotide-mediated modulation of downstream pathways.