PROS1 and Hypoalbuminemia: CDG patients with defective N-glycosylation also share common laboratory deviations such as hypertransaminasemia (most prominent in MPI-CDG, but also in others), hypoalbuminemia, low plasma cholesterol, laboratory indices of hypothyroidism (the actual cause of which is often a deficiency of the thyroxin-binding globulin), cytopenias, proteinuria, and serum clotting factor deficiencies (such as protein S, protein C, AT III, and factors IX, XI, II, V, VII, VIII, and X) (Truin et al., 2008; Verheijen et al., 2020).