Partial H (beta 1H) deficiency and glomerulonephritis in two families.
H (beta 1H) controls the C3b amplification loop by its ability to displace Bb from the alternative pathway convertase, C3b,Bb, and acts as a cofactor with I (C3b inactivator) to produce inactive C3b. Serum C3 levels are dependent to a large extent on the levels of H and I. Partial H deficiency was found in two families. The index case in Family 1 had vasculitis, thrombocytopenia, proteinuria, and depressed serum H and C3 levels. The index case in Family 2 had depressed serum H and B (Factor B) levels and IgA nephropathy which progressed to renal failure. His sister also had IgA nephropathy and depressed serum H and C3 levels. The depressed serum C3 level, B level, and H level could be responsible for the development of the immune diseases found in some members of these families.
D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D003176:Complement C3 / Q000096:biosynthesis / Q000235:genetics; D003180:Complement C3b Inactivator Proteins / Q000096:biosynthesis*; D017242:Complement Factor H; D005260:Female; D005921:Glomerulonephritis / Q000235:genetics / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D010641:Phenotype; D011817:Rabbits
C493495:CFH protein, human; D003176:Complement C3; D003180:Complement C3b Inactivator Proteins; D007070:Immunoglobulin A; D017242:Complement Factor H