Which of the following is incorrect about Klinefelter's syndrome ?

Options

A. A chromosomal disorder
B. Karyotype of 44 `+` XXY
C. Gynaecomastia
D. Fertile males

Answer

To determine which statement about Klinefelter's syndrome is incorrect, let's analyze each option step by step:

### Step 1: Understanding Klinefelter's Syndrome
Klinefelter's syndrome is a genetic condition that affects males, characterized by the presence of an extra X chromosome. This results in a chromosomal pattern of 47 chromosomes, specifically 44 autosomes and 2 sex chromosomes (XXY).

### Step 2: Evaluating the Options
1. **Chromosomal Disorder**:
- Klinefelter's syndrome is indeed a chromosomal disorder caused by the presence of an extra X chromosome.
- **Conclusion**: This statement is **correct**.

2. **Karyotype of 44 + XXY**:
- The karyotype for Klinefelter's syndrome is 44 autosomes plus 2 sex chromosomes (XXY), which totals to 47 chromosomes.
- **Conclusion**: This statement is **correct**.

3. **Gynecomastia**:
- Gynecomastia, which is the development of breast tissue in males, is a common feature of Klinefelter's syndrome. It results from hormonal imbalances associated with the extra X chromosome.
- **Conclusion**: This statement is **correct**.

4. **Fertile Males**:
- Males with Klinefelter's syndrome are typically sterile due to low testosterone levels and reduced sperm production. They often have very few or no viable sperm.
- **Conclusion**: This statement is **incorrect**.

### Final Answer
The incorrect statement about Klinefelter's syndrome is that affected individuals are "fertile males." Therefore, the answer is **Option D: Fertile males**.

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