Patients with nephrotic syndrome had very low mean serum CP (235.4±88.3 mg/L); 37.7% of patients had CP <200 mg/L, 13.9% had CP <150 mg/L, 2.2% had CP <100 mg/L, and two patients had CP <50 mg/L and the possibility of WD had been excluded in these two patients through subsequent clinical follow-up too. This evidence concerns the gene CP and Wilson disease.