Individuals who are deficient in the early complement proteins C1 and C4 are highly susceptible to developing SLE, with C1q deficiency a stronger genetic predictor to the disease (93% of individuals with C1q deficiency, and 75% of individuals with C4 deficiency present SLE-like symptoms) (82). The gene discussed is VTN; the disease is hyperinsulinemic hypoglycemia, familial, 4.