CP and Wilson disease: In one series, 12 of 55 patients with WD had normal CP levels, [18] and in another study, six of 22 patients with WD also had normal CP levels.[19] In a previous study, 10 of 28 children with WD had serum CP >200 mg/L.[20] By contrast, very few patients with WD (1%) had normal CP levels in our study.