The authors established the diagnosis of hepatolenticular degeneration (HLD, Wilson's disease) in eight out of nine asymptomatic subjects suspected of being destined to develop the disease because of the finding of decreased serum ceruloplasmin concentration. Deficiency or absence of ceruloplasmin (less than 20 mg/ 100 ml of serum) is a necessary condition, and elevation of hepatic copper concentration above 100 μg/gm of dry weight is a sufficient condition, for a diagnosis of HLD in asymptomatic persons. The finding of nonspecific histologic changes in the livers of the eight subjects serves to confirm the presence of the disease. If the diagnosis is made, prompt adoption of an "anticopper" therapeutic regimen is recommended.
Sternlieb I, Scheinberg IH. The Diagnosis of Wilson's Disease in Asymptomatic Patients. JAMA. 1963;183(9):747–750. doi:10.1001/jama.1963.03700090067011