NGLY1 and hyperinsulinemic hypoglycemia, familial, 4: Whole-genome and -exome sequencing has recently resulted in the identification of NGLY1 mutations in patients with an autosomal recessive developmental disorder called NGLY1 deficiency (Caglayan et al., 2015; Enns et al., 2014; Heeley and Shinawi, 2015; Need et al., 2012).