A 1-year-old boy has global developmental delay, recurrent seizures, temperature instability and sparse, brittle, steely hair that twists on microscopy (pili torti). He has persistent neutropenia with a hypochromic microcytic anemia that has not responded to three months of oral iron. What is the underlying defect?

• A Impaired intestinal iron absorption due to hepcidin excess
• B Defective ferritin synthesis due to IRP2 mutation
• C Defective cobalamin transport due to intrinsic factor deficiency
• D Defective copper transport caused by mutation in the ATP7A gene ✓

Explanation

Menkes disease is an X-linked disorder of the copper transporter ATP7A producing functional copper deficiency. The combination of kinky hair (pili torti), neurodegeneration, neutropenia and a microcytic anemia unresponsive to iron is characteristic, because ceruloplasmin-dependent iron mobilization fails. Iron studies would show low transferrin-bound iron despite adequate stores, distinguishing it from true iron deficiency, and cobalamin deficiency causes macrocytic rather than microcytic anemia.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.