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: Ophthalmology
Retinitis pigmentosa forms a constituent of all the following syndromes except: 
Select and explain. 
A. Lowe's syndrome, B. Refsum's syndrome, C. Usher's syndrome, D. Hallgren's syndrome
A: Lowe's syndrome
Answer: A: Lowe's syndrome 
Explanation: Ans. Lowe's syndrome