Question

which of the following is not a recessive inherited disorder?
a cystic fibrosis
b phenylketonuria
c sickle-cell disease
d muscular dystrophy

Explanation:

• Cystic fibrosis is an autosomal recessive disorder.
• Phenylketonuria is an autosomal recessive disorder.
• Sickle - cell disease is an autosomal recessive disorder (in the case of sickle - cell anemia, which is the most common form of sickle - cell disease).
• Muscular dystrophy (e.g., Duchenne muscular dystrophy) is an X - linked recessive disorder, but some forms of muscular dystrophy can also be autosomal dominant. Since the question asks for the option that is “NOT a recessive inherited disorder” in the context of typical textbook - style multiple - choice (where the other three are more clearly recessive in their most common forms and muscular dystrophy has non - recessive inheritance patterns in some cases), muscular dystrophy is the answer.

Answer:

D. Muscular dystrophy