C9 deficiency

C9 is a glycoprotein wich has sequence homology to C8alfa, C8beta, C6, and perforin. C9 is produced by hepatocytes, it is cytokine inducible and behaves as an acute phase reactant. Patients with C9 deficiency have reduced levels of C9 in their serum. They possess some serum hemolytic and bactericidal activity but less than in normal serum.

Alternative names

Complement component 9 deficiency


  • Defects of the classical complement cascade proteins


Autosomal recessive