## Core Concept
Wilson's disease, also known as hepatolenticular degeneration, is a rare genetic disorder characterized by excessive accumulation of copper in the body, particularly in the liver, brain, and other vital organs. This accumulation is due to a mutation in the **ATP7B gene**, which plays a crucial role in regulating the transport of copper in the liver. The disease is inherited in an autosomal recessive pattern.

## Why the Correct Answer is Right
The correct answer involves understanding the pathophysiology and clinical manifestations of Wilson's disease. The disease leads to liver disease, neurological symptoms, and psychiatric problems due to copper accumulation. A hallmark of Wilson's disease is the presence of **Kayser-Fleischer rings**, which are copper deposits in the cornea of the eye. The disease is diagnosed through a combination of clinical evaluation, laboratory tests (including liver function tests and serum copper levels), and genetic testing.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because Wilson's disease is not caused by a defect in the transport of iron but rather in the transport of copper.
- **Option B:** This option is incorrect as Wilson's disease is inherited in an autosomal recessive manner, not autosomal dominant.
- **Option C:** While liver disease is a feature of Wilson's disease, stating it as the sole or primary manifestation overlooks the significant neurological and psychiatric aspects of the disease.

## Clinical Pearl / High-Yield Fact
A crucial clinical pearl for Wilson's disease is that it can present with a variety of symptoms, including liver disease (such as hepatitis or cirrhosis), neurological symptoms (such as tremors, difficulty walking, and dystonia), and psychiatric problems. A classic and memorable point is that **Kayser-Fleischer rings** are often seen in patients with neurological manifestations but may be absent in patients with primarily hepatic manifestations.

## Correct Answer Line
**Correct Answer: D.**