Definition:

Late complement component (the final common pathway C5b-C9 components) deficiencies (LCCDs) are all inherited in an autosomal recessive manner. In all cases, homozygous recessive patients have greatly reduced levels of the respective complement component. Generally, patients with deficiencies of C5, C6, C7, or C8 are particularly susceptible to systemic infections with Neisseria meningitidies and N. gonorrhoeae. Infections are rarely fulminant but are often recurrent and frequently involve unusual serotypes of the organism.