Complement inherited deficiencies

The clinical importance of the complement system is demonstrated by the disease associations seen in inherited or secondary deficiencies of the various components. Several of the more important of these are listed in Table 20-9. Most of the complement components also demonstrate genetic polymorphism. The genetic aspects of C3 and C4 are discussed in the individual sections following. 

Wanders, R.J., van Roermund, C.W., Brul, S., Schutgens, R.B. Tager, J.M. (1992) J. Inherit Metab. Dis. 15, 385-388. Bifunctional enzyme deficiency identification of a new type of peroxisomal disorder in a patient with an impairment in peroxisomal beta-oxidation of unknown aetiology by means of complementation analysis. 

Deficiency of C6 may be quite common in outbred rabbits . Up to 5% of rabbits have the deficiency. The defect is inherited as an autosomal recessive but the heterozygotes can be easily detected . C6 deficient rabbits produce antibody to homologous C6 so that the presence of CRM+ C6 in their serum is unlikely. Although C6 deficient rabbits appear healthy and have no gross immunological defect, they do have a clotting defect . This appears to result from a peculiarity of the rabbit platelet which requires all complement components for the release of initiating factors. Blood from a C6 deficient human clots normally . ... 

---