CFHR5

This gene is a member of a small complement factor H (CFH) gene cluster on chromosome 1. Each member of this gene family contains multiple short consensus repeats (SCRs) typical of regulators of complement activation. The protein encoded by this gene has nine SCRs with the first two repeats having heparin binding properties, a region within repeats 5-7 having heparin binding and C reactive protein binding properties, and the C-terminal repeats being similar to a complement component 3 b (C3b) binding domain. This protein co-localizes with C3, binds C3b in a dose-dependent manner, and is recruited to tissues damaged by C-reactive protein. Allelic variations in this gene have been associated, but not causally linked, with two different forms of kidney disease: membranoproliferative glomerulonephritis type II (MPGNII) and hemolytic uraemic syndrome (HUS). [provided by RefSeq, Jan 2010]

Full Name

Complement Factor H Related 5

Function

Involved in complement regulation. The dimerized forms have avidity for tissue-bound complement fragments and efficiently compete with the physiological complement inhibitor CFH.

Biological Process

Complement activation, alternative pathway Source: UniProtKB
Cytolysis by host of symbiont cells Source: UniProtKB
Negative regulation of protein binding Source: UniProtKB
Regulation of complement activation Source: Reactome

Cellular Location

Secreted

Involvement in disease

Defects in CFHR5 have been found in patients with atypical hemolytic uremic syndrome and may contribute to the disease. Atypical hemolytic uremic syndrome is a complex genetic disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, renal failure and absence of episodes of enterocolitis and diarrhea. In contrast to typical hemolytic uremic syndrome, atypical forms have a poorer prognosis, with higher death rates and frequent progression to end-stage renal disease. Susceptibility to the development of atypical hemolytic uremic syndrome can be conferred by mutations in various components of or regulatory factors in the complement cascade system. Other genes may play a role in modifying the phenotype.
CFHR5 deficiency (CFHR5D): A progressive disease characterized by glomerulonephritis, hematuria, renal failure, end-stage renal disease, subendothelial and mesangial glomerular C3 deposits, mesangial matrix expansion, increased glomerular cellularity, and segmental capillary wall thickening. Hematuria may become apparent after respiratory infections.