**Core Concept:** Wilson disease is a genetic disorder characterized by the accumulation of copper in the liver, brain, and other tissues. It is caused by mutations in the ATP7B gene, which plays a role in copper transport and regulation. The ATP7B gene is responsible for encoding a transmembrane protein called copper-transporting adenosine triphosphatase, involved in the elimination of copper from the cell.

**Why the Correct Answer is Right:** The correct answer, chromosome 13 (Option C), is where the ATP7B gene responsible for Wilson disease is located. This gene encodes the copper-transporting adenosine triphosphatase protein, which is essential for copper homeostasis and excretion. Mutations in this gene lead to the accumulation of copper in body tissues, resulting in the clinical manifestations of Wilson disease.

**Why Each Wrong Option is Incorrect:**

A. Chromosome 6 (Option A) does not contain the ATP7B gene for Wilson disease.
B. Chromosome 11 (Option D) is not the correct chromosome for the ATP7B gene.
C. Chromosome 13 (Option C) has the ATP7B gene, making it the correct answer, while A, B, and D are incorrect.

**Clinical Pearl:** Wilson disease is an important consideration in patients presenting with copper-related neurological symptoms, cirrhosis, or Kayser-Fleischer rings (a copper-rich ring in the cornea). Diagnosis is confirmed through genetic testing or liver biopsy, and treatment involves chelation therapy to remove copper from the body.