This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculoskeletal system, Subject name: Pathology
Cleidocranial dysplasia is due to a defect in which gene 
Select and explain. 
A. RANKL, B. RUNX2, C. HOXD13, D. COL2A1
B: RUNX2
Answer: B: RUNX2 
Explanation: Loss-of-function mutations in the RUNX2 gene result in cleidocranial dysplasia, an autosomal dominant disorderIt is characterized by patent fontanelles, delayed closure of cranial sutures, Wormian bones (extra bones that occur within a cranial suture), delayed eruption of secondary teeth, primitive clavicles, and sho height.Robbins pathology 9e pg: 1184