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
The otopathology in the case of Alpo syndrome is: 
Select and explain. 
A. Defect in the cochlear basement membranes, B. Defect in conduction, C. Defect in the vestibulocochlear nerve, D. None of the above
A: Defect in the cochlear basement membranes
Answer: A: Defect in the cochlear basement membranes 
Explanation: The otopathology in AS is a defect in the cochlear basement membranes. Type IV collagen chains in the active tuning of the basilar and tectorial membrane which is an essential step in frequency discrimination and amplification of auditory signals are affected. Ref: Dan Med Bull 2009; 56:105-52