Gene involved in Retinoblastoma
**Core Concept**
The question is testing knowledge of the genetic basis of retinoblastoma, a malignant tumor of the retina. Retinoblastoma is associated with mutations in a specific tumor suppressor gene. This gene plays a crucial role in regulating cell growth and division, and its malfunction can lead to cancer.
**Why the Correct Answer is Right**
The correct answer is RB1, which encodes the retinoblastoma protein (pRb). The RB1 gene is a tumor suppressor gene that regulates the cell cycle by inhibiting the transition from G1 to S phase. Mutations in RB1 lead to the loss of its tumor suppressor function, resulting in uncontrolled cell growth and tumor formation. The retinoblastoma protein interacts with E2F transcription factors to prevent the expression of genes required for cell cycle progression.
**Why Each Wrong Option is Incorrect**
* **Option A:** This is not a known gene associated with retinoblastoma.
* **Option B:** TP53 is a different tumor suppressor gene involved in Li-Fraumeni syndrome, not retinoblastoma.
* **Option C:** This is not a recognized gene related to retinoblastoma.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that retinoblastoma is associated with a high risk of secondary malignancies, particularly osteosarcoma and melanoma, in patients with bilateral retinoblastoma or those with a family history of the disease.
**Correct Answer: A. RB1**