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
Osteogenesis imperfect defect in - 
Select and explain. 
A. Collagen type I, B. Elastin, C. Collagen type IV, D. basement membrane
A: Collagen type I
Answer: A: Collagen type I 
Explanation: Ans. is 'a' i.e., Collagen type I o Osteogenesis imperfecta also known as brittle bone disease, or "Lobstein syndrome" is a congenital bone disorder. o People with 01 are born with defective connective tissue, or without the ability to make it, usually because of a deficiency of Type-I collagen. o This deficiency arises from an amino acid substitution of glycine to bulkier amino acids in the collagen triple helix structure.