Abstract
Background: Congenital disorders of glycosylation (CDG) are clinically and biochemically versatile disorders affecting the N- or O-glycosylation of proteins or lipids. The rapidly growing number of distinct CDG increasingly makes clear that a comprehensive screening for the vast majority of CDG is not possible on a simple basis. Objective: The prevailing methods for the screening and the diagnosis of CDG are presented, showing the potential and the limits of the diagnostic and screening tools used, orientated at suitability for daily use. Conclusion: Although valid and comprehensive diagnostic tests for CDG type I exist, there are limitations in the diagnosis of CDG type II, and many undiagnosed CDG type IIs must be expected. The apparent limitations of the methods used at present imply a necessity for new and broad diagnostic tools that comprise modern methodology to meet the requirements for screening tools.