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: Dental
In congenital dystrophic variety of epidermolysis bullosa, mutation is seen in the gene conding for – 
Select and explain. 
A. Laminin 4, B. Collagen type 7, C. Alpha 6 integerin, D. Keratin 14
B: Collagen type 7
Answer: B: Collagen type 7 
Explanation: Dystrophic epidermolysis bullosa (dermal type EB) there is defect in the enzyme collegenase and type 7 collegan.