Gynaecomastia is a characteristic of

Options

A. A genetic disorder caused by trisomy of sex chromosome in females
B. A genetic disorder caused by trisomy of autosomal chromosome in females
C. A genetic disorder caused by trisomy of sex chromosome in males
D. A genetic disorder caused by trisomy of autosomal chromosome in males

Answer

### Step-by-Step Solution:

1. **Understanding Gynaecomastia**:
- Gynaecomastia is a medical condition characterized by the enlargement of breast tissue in males. This condition is often caused by an imbalance between estrogen (female sex hormone) and testosterone (male sex hormone) levels in the body.

2. **Identifying the Cause**:
- The primary cause of gynaecomastia is an increase in estrogen levels, which can occur due to various factors including hormonal changes, certain medications, or underlying health conditions.

3. **Linking to Klinefelter Syndrome**:
- Gynaecomastia is one of the symptoms associated with Klinefelter syndrome. Klinefelter syndrome is a genetic condition that occurs in males who have an extra X chromosome, resulting in a chromosomal pattern of XXY instead of the typical XY.

4. **Analyzing the Options**:
- The question provides several options regarding the characteristics of gynaecomastia:
- Option A: Genetic disorder caused by trisomy of sex chromosome in females - Incorrect, as gynaecomastia occurs in males.
- Option B: Genetic disorder caused by trisomy of autosomal chromosome in males - Incorrect, since this condition is related to sex chromosomes, not autosomal chromosomes.
- Option C: Genetic disorder caused by trisomy of sex chromosome in males - Correct, as Klinefelter syndrome involves an extra X chromosome in males.

5. **Conclusion**:
- The correct answer is Option C: "A genetic disorder caused by trisomy of sex chromosome in male," as it accurately describes the condition associated with gynaecomastia.