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: Pathology
Which of the following diseases of the skin is the most
likely to be associated with partial anodontia? 
Select and explain. 
A. erythema multiformae, B. hereditary ectodermal dysplasia, C. keratosis follicularits, D. lichen Onus
B: hereditary ectodermal dysplasia
Answer: B: hereditary ectodermal dysplasia 
Explanation: Ectodermal dysplasia is characterized by congenital dysplasia of ectodermaL structures, manifested as hypohidrosis (partial or complete absence of sweat glands) hypotrichosis and hypodontia or partial anodontia.
Two types

Hypohidrotic (Christ-Siemens-Touraine syndrome) most common type and includes dental manifestations.
Hidrotic (Clouston syndrome)- no specific dental defects are seen.