Wilson's disease is characterised by copper accumulation in hepatocytes. The protein defective in Wilson's disease is a:

• A Ceruloplasmin copper-binding protein
• B Metallothionein copper-storage protein
• C P-type ATPase copper transporter (ATP7B) responsible for biliary copper excretion ✓
• D ATP7A copper transporter involved in intestinal copper absorption

Explanation

Wilson's disease (autosomal recessive) is caused by mutation in ATP7B encoding a P-type ATPase copper transporter located in hepatocyte trans-Golgi network. ATP7B is responsible for incorporating copper into ceruloplasmin for secretion and for excreting excess copper into bile; its loss causes copper accumulation in hepatocytes, spilling into blood and depositing in brain (basal ganglia), cornea (Kayser-Fleischer rings), kidneys, and joints. ATP7A is defective in Menkes disease (impaired intestinal copper absorption); ceruloplasmin is secondarily low in Wilson's but is not the primary defect.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.