The target antigen in dermolytic variant of epidermolysis bullosa is:
**Core Concept**
The dermolytic variant of epidermolysis bullosa, also known as dystrophic epidermolysis bullosa, is a genetic disorder characterized by **fragile skin** and **blistering**. This condition is caused by mutations in the **COL7A1 gene**, which encodes for **type VII collagen**.
**Why the Correct Answer is Right**
The correct answer is related to the **type VII collagen**, which is essential for **anchoring fibrils** that secure the **epidermis** to the **dermis**. In the dermolytic variant of epidermolysis bullosa, the target antigen is **type VII collagen**, as autoantibodies or genetic mutations affect this protein, leading to skin blistering.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not relate to the specific antigen involved in the dermolytic variant of epidermolysis bullosa.
**Option B:** Similarly, this option is incorrect as it is not associated with the **type VII collagen** or the anchoring fibrils.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **type VII collagen** plays a crucial role in maintaining skin integrity, and its dysfunction leads to severe skin blistering.
**Correct Answer:** D. Type VII collagen.