Mondo Description A rare genetic disorder with an autosomal recessive pattern of inheritance. It is caused by the ineffective or decreased biosynthesis of the fifth complement component, C5. C5 deficiency may also be acquired acutely post-infection. If C5 is adequately synthesized, its rapid depletion may result in a functional deficiency. Clinical signs of the inherited deficiency present within the second decade of life and are consistent with the signs of recurrent systemic infection. Deficiency of serum C5 and its major cleavage product, C5b, a component of the membrane attack complex, increases susceptibility to Neisserial infections.

Uniprot Description A rare defect of the complement classical pathway associated with susceptibility to severe recurrent infections, predominantly by Neisseria gonorrhoeae or Neisseria meningitidis.

Disease Ontology Description A complement deficiency that is characterized by susceptibility to recurrent bacterial infections especially to infections of enveloped organisms, and has_material_basis_in mutation in the complement component 5 (C5) gene on chromosome 9q33.2 that encodes the fifth component of complenent, a part of the innate immune system.