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
Duchenne's muscular dvstrophy- 
Select and explain. 
A. X-L inked dominant, B. X-Linked recessive, C. Autosomal dominant, D. Autosomal recessive
B: X-Linked recessive
Answer: B: X-Linked recessive 
Explanation: Ans. is 'b' i.e., X-linked recessive o Duchenne and Becker's muscular dystrophy are X-like recessive,o So expression of gene is essentially confirmed in males.o Females are affected only if X-chromosome carrying the normal allele is lost or inactivated.