Hereditary retinoblastoma develop from the following chromosomal deletions
**Core Concept**
Hereditary retinoblastoma is a rare genetic disorder characterized by the development of malignant tumors in one or both eyes. It is caused by mutations or deletions in the RB1 tumor suppressor gene, which plays a crucial role in regulating cell growth and division.
**Why the Correct Answer is Right**
The correct answer involves the deletion of a specific chromosome that contains the RB1 gene. The RB1 gene acts as a tumor suppressor by inhibiting the progression of cells from the G1 phase to the S phase of the cell cycle. Deletions or mutations in the RB1 gene lead to the loss of its tumor suppressor function, resulting in uncontrolled cell growth and tumor formation. The specific chromosomal deletion associated with hereditary retinoblastoma is 13q14.2, which is a region on the long arm of chromosome 13.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct chromosomal region associated with hereditary retinoblastoma.
**Option B:** This option is incorrect because it is a different chromosomal region associated with a different genetic disorder.
**Option C:** This option is incorrect because it is a chromosomal region associated with a different type of cancer.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that hereditary retinoblastoma is an autosomal dominant disorder, meaning that a single copy of the mutated gene is sufficient to cause the condition. This is in contrast to autosomal recessive disorders, which require two copies of the mutated gene to manifest.
**Correct Answer:** D.