Which of the following cannot be detected in a developing foetus by amniocentesis?

Options

A. Down syndrome
B. Jaundice
C. Klinefelter syndrome
D. Sex of the foetus

Answer

**Step-by-Step Solution:**

1. **Understanding Amniocentesis**: Amniocentesis is a medical procedure used during pregnancy to extract amniotic fluid from the amniotic sac surrounding a developing fetus. This procedure is typically performed between the 14th and 16th weeks of pregnancy.

2. **Components of Amniotic Fluid**: The amniotic fluid contains fetal cells, which can be analyzed for various genetic and chromosomal conditions. The cells obtained can provide information about the fetus's genetic makeup.

3. **Conditions Detected by Amniocentesis**:
- **Down Syndrome**: This is a chromosomal disorder caused by an extra copy of chromosome 21. It can be detected through chromosomal analysis of the fetal cells obtained from the amniotic fluid.
- **Klinefelter Syndrome**: This is another chromosomal disorder that occurs in males when they have an extra X chromosome (XXY). Like Down syndrome, it can also be detected through amniocentesis.
- **Sex of the Fetus**: Amniocentesis can also be used to determine the sex of the fetus by analyzing the chromosomes present in the fetal cells.

4. **Condition Not Detected by Amniocentesis**:
- **Jaundice**: Jaundice is not a chromosomal disorder; rather, it is a metabolic condition characterized by yellowing of the skin and eyes due to high bilirubin levels. It is not detectable through amniocentesis because it does not involve chromosomal analysis.

5. **Conclusion**: Based on the information above, the correct answer to the question "Which of the following cannot be detected in a developing fetus by amniocentesis?" is **jaundice**.

**Final Answer**: Jaundice (Option 2)

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