DAG1 and muscular dystrophy: Deficiency in DPM1 has been associated with CDG syndrome due to deficient protein N-glycosylation, whereas defect in DPM3 causes a muscular dystrophy associated with abnormal O-mannosylation of dystroglycan (Waetzig et al., 2010; Barone et al., 2012; Yang et al., 2013; Bursle et al., 2017).