Cerebral lipid and protein abnormalities in Menkes' steely-hair disease

Menkes' steely-hair disease is characterized by abnormal copper metabolism accompanying progressive cerebral degeneration. Cerebral lipids and proteins of an infantile male patient with Menkes' disease were analyzed. The major lipid components in myelin, which included free cholesterol, phospholipids, galactosylceramide, sulfatide, and GM4 ganglioside were markedly decreased, indicating that the myelin was severely damaged by the defective copper metabolism. The degeneration of the myelin was also indicated by decrease in myelin basic protein and proteolipid protein, whereas gliosis in the white matter was biochemically confirmed by prominent increase in glial fibrillary acidic protein. Fatty acid analyses of phospholipids in the white matter revealed that the unsaturated fatty acids were severely decreased in phosphatidylethanolamine, phosphatidylcholine, and phosphatidylserine, and that the long chain fatty acids were also decreased in sphingomyelin. As both the desaturation of fatty acids in glycerophospholipids and the elongation of fatty acids in sphingomyelin are in general thought as markers for myelination, the results suggest that the progressive cerebral degeneration in the disease is due to dysmyelination rather than demyelination. The dysmyelination seemed to be supported by the fact that cholesterol ester which is thought as a marker for demyelination, showed no increase in the brain.