Which of the following is correct about phenylketonuria?

Options

A. It is an example of pleiotropy
B. It is an autosomal dominant disease
C. It is caused due to single gene mutation
D. Both (A) and (C)

Answer

To solve the question regarding phenylketonuria (PKU), we need to analyze each of the options provided and determine which statements are correct.

### Step-by-Step Solution:

1. **Understanding Phenylketonuria (PKU)**:
- PKU is a genetic disorder that results in the accumulation of phenylalanine in the body due to a deficiency of the enzyme phenylalanine hydroxylase. This enzyme is responsible for converting phenylalanine into tyrosine.

2. **Analyzing the Options**:
- **Option A**: "It is an example of pleiotropy."
- Pleiotropy refers to a single gene affecting multiple traits. In the case of PKU, the defective gene affects various systems in the body, leading to multiple symptoms. Therefore, this statement is correct.

- **Option B**: "It is an autosomal dominant disease."
- PKU is actually classified as an autosomal recessive disorder, not dominant. This means that an individual must inherit two copies of the mutated gene (one from each parent) to express the disorder. Therefore, this statement is incorrect.

- **Option C**: "It is caused due to single gene mutation."
- PKU is indeed caused by a mutation in a single gene located on chromosome 12. This statement is correct.

- **Option D**: "Both A and C."
- Since both statements A and C are correct, this option is also correct.

3. **Conclusion**:
- The correct answer to the question "Which of the following is correct about phenylketonuria?" is **Option D: Both A and C**.

### Final Answer:
The correct statements about phenylketonuria are that it is an example of pleiotropy and it is caused due to a single gene mutation. Therefore, the answer is **Option D: Both A and C**.