Wilson disease leads to copper accumulation in the liver, brain, and Kayser-Fleischer rings in the cornea. The defective protein is:

• A Ceruloplasmin — the copper transport protein in blood
• B HFE protein — the hemochromatosis gene product that regulates iron absorption
• C Alpha-1 antitrypsin — a serine protease inhibitor that when misfolded accumulates in hepatocytes
• D ATP7B — a copper-transporting P-type ATPase responsible for biliary copper excretion and ceruloplasmin incorporation ✓

Explanation

Wilson disease is caused by mutations in ATP7B (chromosome 13), which encodes a P-type ATPase that incorporates copper into ceruloplasmin and excretes excess copper into bile. Loss of ATP7B leads to copper accumulation in hepatocytes, then spillover into brain (basal ganglia), cornea, and kidneys. Ceruloplasmin is low but is not the defective protein. HFE mutations cause hereditary hemochromatosis.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.