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 Gynecomastia**: Gynecomastia is defined as the enlargement of breast tissue in males. This condition indicates a hormonal imbalance, often associated with an increase in estrogen or a decrease in testosterone.

2. **Identifying the Genetic Basis**: The question presents four options regarding the genetic disorder associated with gynecomastia. We need to identify which option correctly describes the genetic cause of this condition.

3. **Evaluating the Options**:
- **Option 1**: A genetic disorder caused by trisomy of sex chromosomes in females. (Incorrect, as gynecomastia occurs in males, not females.)
- **Option 2**: A genetic disorder caused by trisomy of autosomal chromosomes in females. (Incorrect, as this does not relate to gynecomastia in males.)
- **Option 3**: A genetic disorder caused by trisomy of sex chromosomes in males. (This is correct; it relates to Klinefelter syndrome, which is characterized by the presence of an extra X chromosome in males.)
- **Option 4**: A genetic disorder caused by trisomy of autosomal chromosomes in males. (Incorrect, as it does not specifically relate to gynecomastia.)

4. **Conclusion**: The correct answer is **Option 3**, which states that gynecomastia is a characteristic of a genetic disorder caused by trisomy of sex chromosomes in males. This is specifically linked to Klinefelter syndrome, where males have an extra X chromosome (47, XXY).