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: Pediatrics
Wilson disease is caused by defect in 
Select and explain. 
A. ATP 7A mutation, B. ATP 6A mutation, C. ATP 6B mutation, D. ATP 7B mutation
D: ATP 7B mutation
Answer: D: ATP 7B mutation 
Explanation: ATP 7B gene on chromosome 13 is mutated in Wilson disease.