The main indications for a renal biopsy in children include persistent microscopic hematuria with or without proteinuria, recurrent gross hematuria, steroid-dependent and steroid resistant nephrotic syndrome (NS), distinction of nephrotic syndrome/nephritic syndrome, persistently low C3 in acute post-streptococcal GN, acute renal failure of unknown etiology, cyclosporine protocol biopsy, renal involvement in systemic lupus erythematosus (SLE) and lastly, staging of HSP nephritis [3–5]. This evidence concerns the gene C3 and systemic lupus erythematosus.