We present two siblings with a previously undescribed congenital disorder of glycosylation (CDG). The first child died in utero with severe hydrops fetalis and the second presented following preterm delivery with respiratory insufficiency, generalised edema and a protein-losing enteropathy. Both had a similar pattern of facial dysmorphism and joint contractures. The diagnosis of CDG-I was made following the birth of the second child based on the serum transferrin isoform pattern. CDG-Ia and -Ib were excluded by specific enzyme analysis. Joint contractures are a relatively uncommon finding in CDG, although fetal hydrops (CDG-Ia) and protein-losing enteropathy (CDG-Ib) are well recognized. CDG must be considered in the differential diagnosis of hydrops fetalis, congenital hypoproteinemia and death in early infancy, particularly when associated with dysmorphic features.