The cause of<unk>  is genetics (though cases of an acquired nature do exist post infection). The majority of<unk> es are inherited as autosomal recessive conditions, while properdin deficiency occurs through X-linked inheritance. MBL deficiency can be inherited by either manner. Inherited * Properdin deficiency is an X-linked disorder that also causes susceptibility to Neisseria infections. * C1-inhibitor deficiency or hereditary angioedema will have low C4 with normal C1 levels. Acquired Acquired hypocomplementemia may occur in the setting of bone infections (osteomyelitis), infection of the lining of the heart (endocarditis), and cryoglobulinemia. Systemic lupus erythematosus is associated with low C3 and C4. Membranoproliferative glomerulonephritis usually has low C3.
Complement deficiency
Complement 2 deficiency
Complement 3 deficiency
Terminal complement pathway deficiency
IgG deficiency
T cell deficiency
Neutrophil-specific granule deficiency
Leukocyte adhesion deficiency