This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Pathology
The genetic defect in Dubin-Johnson Syndrome is 
Select and explain. 
A. Mutation in gene for multiple drug resistance protein 2, B. Mutation in gene UDP- glucuronyl transferase, C. Mutation of chromosome 23, D. Flash mutations
A: Mutation in gene for multiple drug resistance protein 2
Answer: A: Mutation in gene for multiple drug resistance protein 2 
Explanation: Dubin-Johnson syndrome is a rare, autosomal recessive, benign disorder that causes an isolated increase of conjugated bilirubin in the serum. Classically, the condition causes a black liver due to the deposition of a pigment similar to melanin. Refer robbins 9/e