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: Skin
Defect seen in Vitiligo is: September 2010 
Select and explain. 
A. Absent melanosomes, B. Absent melanocytes, C. Reduction in melanin synthesis, D. Reduction in number of melanocytes
B: Absent melanocytes
Answer: B: Absent melanocytes 
Explanation: Ans. B: Absent melanocytes Vitiligo is a chronic disorder that causes depigmentation of patches of skin. It occurs when melanocytes, the cells responsible for skin pigmentation, die or are unable to function. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmune, genetic, oxidative stress, neural, or viral causes.