Impairment of human brain development: glycoconjugate and lipid changes in congenital athyroidism

The brain glycoconjugates, glycosidases and lipids have been studied in a case of human congenital athyroidism never treated with hormonal replacement. Increase of membrane-bound mucopolysaccharides has been found in the grey matter. Total lipids in the white matter, and phospholipids, and total glycolipids and cholesterol in both white and grey matter were reduced. Sialic acid (NeuNAc) and hexosamines in the cytosol grey matter were significantly raised, while they were reduced in the membrane-bound grey fraction. These biochemical findings confirm impairment of the myelination process in human hypothyroidism as is well established in experimental hypothyroidism. The significant changes in the carbohydrate moieties of the brain glycoproteins focus attention on complex alterations of structure and function of the cell plasma membranes.