Ring chromosome is a result of?
**Ring Chromosome**
**Core Concept**
A ring chromosome is a type of chromosomal abnormality where a chromosome breaks and fuses together, forming a circular structure. This type of chromosomal rearrangement can occur in any chromosome, but it is most commonly seen in the short arm of chromosome 14 (14p). The formation of a ring chromosome disrupts the normal gene expression and can lead to various genetic disorders.
**Why the Correct Answer is Right**
The formation of a ring chromosome is a result of a process called end-to-end fusion, where the broken ends of the chromosome fuse together, creating a circular structure. This type of chromosomal rearrangement can occur due to errors during meiosis or mitosis. The presence of a ring chromosome can lead to unbalanced genetic material, resulting in various genetic disorders, including growth and developmental abnormalities, intellectual disability, and increased risk of cancer.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify the correct type of chromosomal rearrangement that leads to the formation of a ring chromosome.
**Option B:** This option is incorrect as it refers to a different type of chromosomal abnormality, where a segment of a chromosome is deleted.
**Option C:** This option is incorrect as it refers to a different type of chromosomal rearrangement, where two or more chromosomes break and fuse together.
**Clinical Pearl / High-Yield Fact**
The presence of a ring chromosome can lead to various genetic disorders, and it is essential to diagnose and manage these conditions promptly to prevent long-term complications. A high index of suspicion is required to identify patients with ring chromosomes, and genetic counseling should be offered to families affected by these conditions.
**Correct Answer: D.**