Scientific background:

Summary: The gene C3 encodes a crucial complement component. Loss-of-function mutations result in autosomal recessive C3 deficiency whereas gain-of-function mutations have been observed in atypical HUS. Some polymorphisms have been associated with age-related macula degeneration.

Methodology:

Literature: 

Maller JB et al. (2007) Variation in complement factor 3 is associated with risk of age-related macular degeneration.
Brown KM et al. (2006) Influence of donor C3 allotype on late renal-transplantation outcome.
Yates JR et al. (2007) Complement C3 variant and the risk of age-related macular degeneration.
Botto M et al. (1990) Molecular basis of polymorphisms of human complement component C3.
Fang CJ et al. (2008) Membrane cofactor protein mutations in atypical hemolytic uremic syndrome (aHUS), fatal Stx-HUS, C3 glomerulonephritis, and the HELLP syndrome.
Loirat C et al. (2008) Complement and the atypical hemolytic uremic syndrome in children.
Nürnberger J et al. (2009) Eculizumab for atypical hemolytic-uremic syndrome.