Inherited Deficiency of the Seventh Component of Complement Associated with Nephritis

Deficiency of c7 with systemic lupus erythematosus. solubilization of immune complexes in complement‐deficient sera

“…C7 deficiency was also suggested by the reaction of lysis in gels. Previous studies have demonstrated that C7-deficient serum has a marked capacity to generate persisting C% in agarose and thus form a distinctive pattern of reactive lysis in the absence of primary lysis, which seems to be diagnostic of C7 deficiency (26). Identical studies in the patient reported here confirmed the previous findings and emphasized the ease of demonstration of this deficiency.…”

“…Identical studies in the patient reported here confirmed the previous findings and emphasized the ease of demonstration of this deficiency. The inability to obtain serum samples from family members in Mexico precluded definitive identification of the hereditary nature of this deficiency; however, an autosomal codominant pattern of inheritance has been demonstrated in 9 other individuals with C7 deficiency (26,(29)(30)(31)(32). Studies of HLA antigens in those patients and their families demonstrated the Aw24 and B12 alleles in only 1 other patient (26); linkage between the HLA-A and B loci and the C7 deficiency locus was not observed in 4 unrelated families (26,(30)(31)(32).…”

Inherited Deficiency of the Seventh Component of Complement Associated with Meningococcal Meningitis: Lack of Serum Bactericidal Activity against Neisseria meningitidis in a Girl with C7 Deficiency and HLA Studies of a C7‐Deficient Japanese Family

“…This mode of inheritance is consistent with an autosomal codominant trait as reported for the other cases of C7D. To date, genetic analysis of the pedigrees of the C7D patients has failed to show a linkage of the HLA-A, -B loci with C7D (7,10,17,19,21). Family studies on C7 deficiency and the HLA system revealed no genetic linkage of C7 deficiency either with HLA-A and -B loci or with HLA-C and -DR loci (Fig.…”

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

“…Hereditary defects of complement components reported thus far mostly involved the classical pathway in human, including Clr (Pickering et al, 1971), Cls (Pondman et al, 1968), C4 (Hauptmann et al, 1974), C2 (Klemperer et al, 1966), C3 (Ballow et al, 1975), C5 (Rosenfeld et al, 1976), C6 (Leddy et al, 1974), C7 (Boyer et al, 1975;Gelgge et aI,, 1977;Nemerow et aL, 1978), and C8 (Petersen et al, 1976), and two inactivators of the complement system, C1 inhibitor (Donaldson and Evans, 1963), and C3b inactivator (Abramson et al, 1971;Thompson and Lachmann, 1977). Few cases of ninth component (C9), the terminal component of the complement sequence, have been reported.…”

“…Thus, levels of C9 protein in serum of normal homozygote (C9, C9), heterozygote (C9, C9), and deficient homozygote (C9, C~) approximately reflected the dosage effect of the wild type and mutant gene. Some of the known defects of complement components in man, including C2 (Klemperer et al, 1966;Fu et al, 1974;Day et al, 1975), C3 (Alper and Rosen, 1979), C5 (Rosenfeld et aI., 1976;Snyderman et al, 1979), C6 (Leddy et al, 1974;Lim et al, 1976;Glass et al, 1978), C7 (Boyer et al, 1975;Gelftge et al, 1977;Nemerow et al, 1978), and C8 (Petersen et al, 1976) appear to be inherited in the same mode as is C9. One of the well documented exceptions to this mode of inheritance is the deficiency of C1 inhibitor (Donaldson and Evans, 1963), causative pathogenesis of hereditary angioedema.…”