what is deposited in Kyser-Fleischer ring-
**Core Concept**
The Kayser-Fleischer ring is a medical sign associated with Wilson's disease, a genetic disorder that causes copper accumulation in the body. The Kayser-Fleischer ring is a deposit of copper that forms around the cornea, specifically in the Descemet's membrane.
**Why the Correct Answer is Right**
In Wilson's disease, the body is unable to excrete copper properly, leading to its accumulation in various tissues, including the cornea. The copper deposited in the Descemet's membrane of the cornea is a result of the abnormal metabolism of copper, which is primarily caused by a defect in the ATP7B gene. This gene plays a crucial role in regulating the transport of copper in the liver.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as the Kayser-Fleischer ring is not associated with iron deposition.
* **Option B:** This option is incorrect as the Kayser-Fleischer ring is not a deposit of melanin.
* **Option C:** This option is incorrect as the Kayser-Fleischer ring is not a deposit of calcium.
**Clinical Pearl / High-Yield Fact**
The Kayser-Fleischer ring is a classic sign of Wilson's disease and is often used as a diagnostic criterion. It is essential to remember that the Kayser-Fleischer ring is a copper deposit, and its presence can help differentiate Wilson's disease from other conditions that may present with similar symptoms.
**Correct Answer: C. Copper**