A 6-month-old infant presents with kinky, sparse, hypopigmented hair, failure to thrive, developmental regression, and hypotonia. Serum copper and ceruloplasmin are low. Which mechanism explains this condition?

• A Defective lysosomal copper transport due to ATP7B mutation
• B Defective copper absorption and transport due to ATP7A mutation ✓
• C Excessive copper absorption due to intestinal transporter upregulation
• D Defective ceruloplasmin synthesis due to hepatic copper accumulation

Explanation

This describes Menkes disease, an X-linked recessive disorder caused by mutations in the ATP7B gene, which encodes a copper-transporting ATPase. This leads to defective intestinal copper absorption and impaired copper transport across the blood-brain barrier, causing copper deficiency in tissues. ATP7A mutations cause Wilson disease (hepatolenticular degeneration). Excessive copper absorption occurs in Indian childhood cirrhosis. Ceruloplasmin deficiency is aceruloplasminemia.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.