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

## **Why the Correct Answer is Right**
The correct answer, autosomal recessive, is right because Wilson's disease manifests only when an individual inherits two defective copies of the *ATP7B* gene—one from each parent. Carriers of the disease, who have one normal and one mutated gene, typically do not display symptoms but can pass the mutated gene to their offspring. The autosomal recessive inheritance pattern explains why the disease often appears to "skip" generations and why siblings of an affected individual have a 25% chance of being affected.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Autosomal dominant inheritance is incorrect because, in autosomal dominant conditions, a single copy of the mutated gene is enough to cause the disease. Wilson's disease does not follow this pattern; individuals must be homozygous for the mutation to express the disease.
- **Option B:** X-linked recessive inheritance is incorrect because Wilson's disease affects both males and females equally and does not link to the X chromosome. The *ATP7B* gene responsible for the disease is located on chromosome 13, which is an autosome.
- **Option C:** Y-linked inheritance is incorrect because Y-linked traits are passed from father to son and are extremely rare. Wilson's disease does not follow this inheritance pattern and affects both genders.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl for Wilson's disease is that it can present with a variety of symptoms, including liver disease, neurological symptoms (such as tremors and difficulty with coordination), and psychiatric problems. A classic diagnostic clue is the presence of Kayser-Fleischer rings, which are copper deposits in the cornea of the eye. Early diagnosis and treatment, often with copper chelating agents or zinc acetate, can significantly improve outcomes.

## **Correct Answer:** . Autosomal Recessive