Carbohydrate-deficient glycoprotein syndromes

Four types of carbohydrate-deficient glycoprotein syndrome have been descri bed, and the cause of two of them has been found. The symptoms and signs of these syndromes are described, with variations that occur at different age s. The commonest is type Ia with an autosomal recessive form of inheritance , and the gene responsible has been mapped to 16p. The typical pathology is atrophy of the cerebellum and brainstem, sometimes also involving the cort ex, although both the pathology and the biochemical deficiencies vary betwe en different types of syndrome. The diagnosis depends firstly on recognisin g the clinical features, including the presence of complications such as th yroid disorders. Then biochemical tests can be carried out, especially chro matographic carbohydrate-deficient transferrin assay and isoelectric focusi ng of serum transferrin. The prognosis depends on the complications, renal, hepatic, and cardiac, bu t affected children will be severely handicapped. Therefore treatment consi sts mainly of coping with the complications, and supporting the child and t he family. Oral infusion of mannose can be effective in type lb disease.