Typically, diagnosis is based on the association of compatible clinical signs and classical biological triad: low ceruloplasmin (Cp), low serum copper and elevated 24-h urinary copper excretion. We conclude from this clinical case that a standard but incomplete serum copper test with no abnormality cannot refute Wilson's disease hypothesis when the clinical suspicion is strong. Kayser-Fleischer ring is present in almost all Wilson's disease patients at disease diagnosis when neurologic symptoms are observed [[2]]. [Extracted from the article]