This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Muscle and Muscular Dystrophies, Subject name: Pediatrics
All of the following are associated with proximal muscle weakness EXCEPT: - 
Select and explain. 
A. Spinomuscular atrophy, B. Duchenis muscular dystrophy, C. Polymyositis, D. Myotonic dystrophy
D: Myotonic dystrophy
Answer: D: Myotonic dystrophy 
Explanation: Ans. is 'd' is myotonic dystrophy The general rule in that:Myopathies have proximal muscle weakness.neuropathies have distal muscle weakness.Myotonic dystrophy is an exception to this general rule and mainly involves the distal muscles.