ABO and congenital disorder of glycosylation: Among the 31 prioritized genes (Fig. 2b), we identified nine genes encoding glycosyltransferases (MGAT5, ST6GAL1, B4GALT1, ABO, ST3GAL4, B3GAT1, FUT8, FUT6, MGAT3); mutations in three are known to lead to congenital disorders of glycosylation (B4GALT1, FUT8, SLC39A8) and four genes have strong experimental support for being regulators of N-glycan biosynthesis genes (HNF1A, IKZF1, RUNX3, SLC39A8)25.