Primary complement defects are associated with an increased risk of developing SLE estimated between 93 % of cases for C1q deficiency (OMIM 613652), 75 % for C4A deficiency (OMIM 614380) and 66 % for C1r and C1s (OMIM 216950) [57]. The gene discussed is C4A; the disease is hyperinsulinemic hypoglycemia, familial, 4.