DPAGT1 and Intellectual disability: Mutations in DPAGT1 also cause congenital disorder of glycosylation type Ij (CDG-Ij, OMIM ref: 608093) (Carrera et al., 2012, Selcen et al., 2014, Wu et al., 2003, Würde et al., 2012), a more severe multisystem syndrome that can cause intellectual disability, epilepsy, microcephaly, severe hypotonia and structural brain anomalies.