The abovementioned seven factors were selected as parameters to establish a regression equation for the diagnosis of IgAN, expressed as P = exp(− 0.808 − 0.051 × age + 0.099 × albumin + 0.766 × hematuria + 0.349 × IgA + 0.134 × IgG + 0.709 × IgA/C3 ratio − 0.028 × eGFR)/[1 + exp(0.808 − 0.051 × age + 0.099 × albumin + 0.766 × hematuria + 0.349 × IgA + 0.134 × IgG + 0.709 × IgA/C3 ratio − 0.028 × eGFR)]. The gene discussed is C3; the disease is Hematuria.