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: Surgery
False about myositis ossificans progressiva (child with heterotopic ossification) is? 
Select and explain. 
A. Pneumonia is common, B. Life longevity is normal, C. Most common site involved is the spine, D. Onset is before 6 years
B: Life longevity is normal
Answer: B: Life longevity is normal 
Explanation: Myositis ossificans progressiva is a autosomal dominant disease is characterized by heterotopic ossification most commonly involving spine and congenital deformities of hand and feet. The disease usually stas before 6 years of age. In myositis ossificans progressiva, the life expectancy is decreased and the commonest cause of death is lung diseases. Ref: Harrison 17/e, Page 2416.