A NEW CAPILLARY ZONE ELECTROPHORESIS METHOD FOR THE SCREENING OF CONGENITAL DISORDERS OF GLYCOSYLATION (CDG)

Background: The Congenital Disorders of Glycosylation (CDG) are an expanding group of metabolic diseases with a broad clinical presentation. We sought to validate a new Capillary Zone Electrophoresis (CZE) method (Sebia CAPILLARYS™ CDT) to screen for CDG. Methods: We analyzed 119 serum samples from children of varying ages and of both sexes to establish a reference range of transferrin glycoforms including CDT (Carbohydrate Deficient Transferrin). We then studied serums from 8 known CDG patients and compared the CZE results to the isoelectric focusing (IEF) profiles. We also analyzed serums after extraction from spotted Guthrie cards. Results: The mean (SD) percentage of transferrin glycoforms is 18.5 (4.4), 78.5 (4.2), 2.5 (1.3) and 0.6 (0.3) for penta-, tetra-, trisialotransferrin and CDT, respectively. There is no statistically significant difference between the different age groups analyzed (0-5, 6-11, 12-15, 16-18, and > 18 years) or between sexes. We observed a good correlation between the CZE and IEF profiles with both fresh serum and serum extracted from Guthrie cards. Conclusions: The Sebia CAPILLARYS™ CDT system is a simple and reliable method to screen for CDG in pediatric and adult patients with an unexplained clinical syndrome, particularly when the nervous system is involved.