This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Orthopaedics
Most common inheritance of Achondroplasia is 
Select and explain. 
A. Sporadic, B. Autosomal dominant, C. Autosomal recessive, D. X-linked recessive
B: Autosomal dominant
Answer: B: Autosomal dominant 
Explanation: (B) Autosomal dominant # ACHONDROPLASIA: This is a condition caused by the failure of normal ossification of bones, mainly the long bones, resulting in dwarfism.> Since growth of the trunk is only marginally affected, the dwarfism is disproportionate; the limbs being out of proportion with the trunk. The shortening is especially marked in the proximal segments of the limbs.> Autosomal dominant condition caused by failure of normal ossification of bones; mainly long bones resulting in dwarfism.> Dwarfism is of disproportionate type, shortening being marked in proximal segments of limbs.> Intelligence is normal