Cri- du chat syndrome is due to chromosomal change involving

Options

A. Duplication
B. Inversion
C. Deletion
D. Translocation

Answer

**Step-by-Step Solution:**

1. **Understanding Cri-du-chat Syndrome**: Cri-du-chat syndrome is a genetic disorder that results from a chromosomal abnormality. It is characterized by a distinctive cry of affected infants, which sounds like a cat's meow.

2. **Identifying Chromosomal Changes**: The question asks which type of chromosomal change is involved in Cri-du-chat syndrome. The options provided are duplication, inversion, deletion, and translocation.

3. **Analyzing Each Option**:
- **Duplication**: This involves an extra segment of a chromosome being attached to a homologous chromosome, leading to the duplication of genes. This is not the cause of Cri-du-chat syndrome.
- **Inversion**: This refers to a segment of a chromosome being reversed end to end. While it is a chromosomal mutation, it does not relate to Cri-du-chat syndrome.
- **Deletion**: This is the loss of a segment of a chromosome. Cri-du-chat syndrome is specifically caused by a deletion of a portion of the long arm of chromosome 5.
- **Translocation**: This involves the rearrangement of chromosomal segments between non-homologous chromosomes. This is also not the cause of Cri-du-chat syndrome.

4. **Conclusion**: Based on the analysis, Cri-du-chat syndrome is caused by a deletion of a part of chromosome 5. Therefore, the correct answer is **deletion**.

**Final Answer**: Cri-du-chat syndrome is due to chromosomal change involving **deletion**.

---