This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
All of the following are true about Wilson disease, except 
Select and explain. 
A. Serum copper level is usually lower than normal, B. Low blood levels of ceruloplasmin, C. Liver damage begins at the age of 18, D. Free copper level is increased in the body
C: Liver damage begins at the age of 18
Answer: C: Liver damage begins at the age of 18 
Explanation: There is impaired biliary copper excretion, resulting in positive copper balance, hepatic copper accumulation. Excess hepatic copper leads to liver damage, which begins as early as three years of age. Serum copper levels are usually lower than normal because of low blood ceruloplasmin. As the disease progresses, non ceruloplasmin serum copper ("free" copper) levels increase which leads to copper buildup in other pas of the body, such as the brain, leading to neurologic and psychiatric disease. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 3188