Among patients with WD, 4.9% (n = 10/204) had normal total Cu levels, 1.6% (n = 3/185) had elevated Cp levels, 3.8% (n = 7/185) had normal Cp levels, and 44.7% (n = 21/47) had normal 24-h UCE (<0.6 μmol/24 h). This evidence concerns the gene CP and Wilson disease.