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: Biochemistry
[{'content': "Which of the following is not true regarding wilson's disease \nSelect and explain. \nA. ATP7B mutation leading to impairment in copper metabolism, B. Most specific screening test is Urinary excretion of copper, C. Gold standard test is liver biopsy, D. KF ring is present in upto 30% cases", 'role': 'user'}, {'content': "Answer: D \nExplanation: KF ring is present in upto 99 % of cases.\nATP 7B mutation results in defective biliary copper excretion into bile as copper can't be incorporated into apoceruloplasmin.\nThus copper accumulates in excess amounts in liver and brain.\nThe copper accumulation in descemets membrane of cornea is manifested as KF rings, in the eye.", 'role': 'assistant'}]