The detection of carbohydrate deficient glycoprotein syndrome by capillary electrophoresis

Abstract

Carbohydrate deficient glycoprotein syndrome (CDGS), which was first reported by Jaeken et al. in 1980, is a disorder in which many glycoproteins are deficient or have reduced carbohydrate side chains. Many subtypes of CDGS have been described based on the isoelectrophoretic patterns of transferrin and on clinical features. Different enzyme deficiencies have been reported in at least four of the subtypes.

Transferrin is a major serum glycoprotein utilized in the diagnosis of CDGS. It has two carbohydrate side chains each ending with two sialic acids. CDGS patients lack portions of these side chains causing different transferrin isoforms. These isoforms can be separated by isoelectric focusing which has been the method of choice for diagnosing these disorders. Capillary electrophoresis can also be used for detecting the aberrant transferrin isoforms in CDGS.

Serum of patients previously diagnosed with CDGS (types Ia, Ib, and IV) was separated by capillary electrophoresis. The transferrin pattern in CDGS patients is easily distinguished from controls in that tetrasialotransferrin is the predominant isoform in normal serum, while in the patient samples both tetra- and disialotransferrin are detected.

Capillary electrophoresis, which takes considerably less time and costs much less than the current methods, is a good choice for detecting patients with CDGS.