Most common genetic factor in Neisseria infection is

Complement deficiencies are said to comprise between 1 and 10% of all primary immunodeficiencies. The genetic deficiency of early components of the classical pathway (C1q, C1r/s, C2, C4) tends to be linked with autoimmune diseases, whereas C5 to C9 deficiency may have enhanced susceptibility to meningococcal disease. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Pg: 232