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: Unknown
Decrease number of melanocyte is seen in: 
Select and explain. 
A. Albinism, B. Piebaldism, C. Ichthyosis, D. Chemical leucoderma
B: Piebaldism
Answer: B: Piebaldism 
Explanation: Piebaldism is a Autosomal dominant disease characterized by patches of skin that lack melanin as a result of defect in migration of melanoblast from neural crest to skin.
Skin biopsy: Hypo melanotic area-few to no melanocytes. Vitiligo: is an acquired disease and similar patch of loss ofmelanin, but the loss develops after birth and progressive. Albinism: Congenital inability to synthesize melanin.