A 2-year-old girl with granulocytopenia developed fever followed by truncal ataxia and progressive neurologic regression. CT demonstrated symmetric low-density areas in the cerebral white matter. Sural nerve biopsy revealed axonal degeneration. Blood lactate levels were high, and serum levels of copper and ceruloplasmin and urinary excretion of copper were low. Cultured skin fibroblasts showed normal copper uptake. Treatment with oral copper administration normalized serum copper and ceruloplasmin levels, blood lactate levels, and granulocyte count. However, copper levels in the CSF were still low, and the patient showed no clinical improvement. We speculated that copper transport across the intestinal wall and across the blood-brain barrier was impaired.