Table 1.

Diseases related to factor H mutations or variants that have potential effects on interactions with CRP, PTX3, C3b or polyanions.

Disease	Factor H or FHR polymorphisms/mutations	Interactions affected	Functional effect of disease-related variant	References
AMD	FH Y402H (domain 7) FHL-1	CRP, polyanions	Insufficient clearance of drusen, inflammation	(46–50)
aHUS	FH mutations in domains 19-20	PTX3, C3b/d, sialic acid	C attack against vascular and blood cells, C-mediated inflammation	(24, 27, 51)
Atherosclerosis	FH I62V (associated with high MMP-8 levels)	C3b	Increased release of MMP-8 from neutrophils	(52)
DDD	FH domains 1-5 (e.g., R83S)	C3b	AP overactivation in the fluid phase, C3b deposition on basement membranes	(51, 53)
	FH Y402H (domain 7)	CRP, polyanions	Inflammation	(26)
C3GN	FHR abnormalities (e.g., hybrids), FHR5	CRP, C3b	Competition with factor H, AP dysregulation	(21)
	FH Y402H (domain 7)	CRP	Inflammation	(26)

AMD, age-related macular degeneration; aHUS, atypical hemolytic-uremic syndrome; DDD, dense deposit disease; C3GN, C3 glomerulonephritis; FHR, factor H-related protein; AP, alternative pathway.