The carbohydrate deficient glycoprotein syndrome in three Japanese children.

We describe 3 children (from two families) with a multisystemic disorder characterized by mental retardation, nonprogressive ataxia, polyneuropathy, hepatopathy during infancy and growth retardation. Due to the clinical similarities to a recently recognized disorder associated with carbohydrate-deficient transferrin, we examined serum transferrin by means of isoelectric focusing, and found increases in disialo transferrin and asialotransferrin. Removal of sialic acid with neuraminidase revealed the same transferrin phenotypes as in their parents. Similarly, carbohydrate-deficient fractions of serum alpha 1-antitrypsin were also detected. Therefore, the diagnosis was made of the recently identified carbohydrate-deficient glycoprotein syndrome. This is a genetic disorder with distinctive clinical features and multiple carbohydrate-deficient glycoproteins. These seem to be the first reported Japanese patients with this syndrome.