Which of the following is mismatched pair of disease and its related symptom ?

Options

A. `{:(" Disease Symptom"),("Phenylketonuria Urine turns black on exposure to air"):}`
B. `{:(" Disease Symptom"),("Down's syndrome Physical and mental retardation"):}`
C. `{:(" Disease Symptom"),("Klinefelter's syndrome Sterile males"):}`
D. `{:(" Disease Symptom"),("Turner's syndrome Sterile females"):}`

Explanation

To determine which of the following pairs of disease and its related symptom is mismatched, we will analyze each option one by one.

### Step-by-Step Solution:

1. **Analyze Option 1: Phenylketonuria**
- **Disease**: Phenylketonuria (PKU) is a metabolic disorder caused by the accumulation of phenylalanine due to a deficiency in the enzyme phenylalanine hydroxylase.
- **Symptom**: The symptom given is "urine turns black on exposure to air."
- **Evaluation**: This symptom is incorrect for PKU; it is actually associated with Alkaptonuria, not Phenylketonuria. Therefore, this pair is mismatched.

2. **Analyze Option 2: Down Syndrome**
- **Disease**: Down Syndrome, also known as Trisomy 21, is caused by the presence of an extra copy of chromosome 21.
- **Symptom**: The symptom given is "physical and mental retardation."
- **Evaluation**: This is a correct symptom associated with Down Syndrome.

3. **Analyze Option 3: Klinefelter Syndrome**
- **Disease**: Klinefelter Syndrome is characterized by the presence of an extra X chromosome in males (XXY).
- **Symptom**: The symptom given is "sterile male."
- **Evaluation**: This is a correct symptom associated with Klinefelter Syndrome.

4. **Analyze Option 4: Turner Syndrome**
- **Disease**: Turner Syndrome occurs in females who have only one X chromosome (XO).
- **Symptom**: The symptom given is "sterile female."
- **Evaluation**: This is also a correct symptom associated with Turner Syndrome.

### Conclusion:
The only mismatched pair is **Option 1: Phenylketonuria and the symptom "urine turns black on exposure to air."** This symptom is actually related to Alkaptonuria.

### Final Answer:
**Option 1 is the mismatched pair.**

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