C7 (complement component 7) encodes an anchor protein th at forms a component of the membrane attack complex (MAC). The complex forms pores in the plasma membrane of target cells and functions in the innate and adaptive immune response. Mutations in this gene can cause a deficiency or complete absence of C7 protein. This causes a rare defect in the complement classical pathway resulting in severe recurrent infections, mainly by Neisseria gonorrhoeae or Neisseria meningitidis.
