Three Cases with Deficiency of the ninth Component of Complement

Immune Complex Glomerulonephritis in a Pregnant Woman with Congenital C9 Deficiency.

“…Associations betweendeficiencies of various componentsof the complement and glomerulonephritis have been identified (6,(9)(10)(11)(12)(13)(14)(15), but there are no reports of an increased incidence of glomerulonephritis associated with C9 deficiency. In a previous report, we described three cases with C9 deficiency who were not susceptible to infections and had no evidence of glomerulonephritis (3). One, a 72-year-old male, was being treated for rheumatoid arthritis.…”

“…Because C9-defective serum demonstrates only about one-third the normal level of total complement activity (CH50), it may be difficult to detect C9 deficiency in routine assays of the complement system. Family studies have shown that C9 deficiency is inherited as an autosomal codominant trait (3,4,7,8). To date, several cases with this defect have been identified in Japan (3)(4)(5)(6) and in the U.S.A. (7,8).…”

“…Family studies have shown that C9 deficiency is inherited as an autosomal codominant trait (3,4,7,8). To date, several cases with this defect have been identified in Japan (3)(4)(5)(6) and in the U.S.A. (7,8). Epidemiologic studies indicate that there is a high frequency of C9 deficiency in Japan (approximately 0.1%), although manyindividuals who have this defect appear to be healthy.…”

A pedigree of deficiency of the ninth component of complement (C9)

“…None of C9 deficient individuals in this family appear to be liable to some specific ill conditions as a result of this deficiency, excepting that the untoward proposita died with a gastric cancer, as did others with a complete C9 deficiency (Inai et al, 1979;Amano et al, 1980;Kawano et al, 1980). It was reported that only one male showed a tendency to have repeated infections (Yukiyama et al, 1979) and a child had an anamnesis 1980).…”

“…Inai et al (1979) were the first to report a case of deficiency of C9 in a 29-yearold healthy woman, and seven families with C9 deficiency have recently been detected in Japan (Kisu et al, 1980;Yukiyama et al, 1979;Amano et al, 1980;Kawano et aI., 1980). Lint et al (1980) recently reported such an occurrence in a Caucasian man.…”