UGDH and developmental and epileptic encephalopathy: Case 18: Decreased expression of the UGDH gene, which is associated with AR Developmental and Epileptic Encephalopathy 84, was identified as an extreme outlier (z-score –4.15, fold change 0.62, p value 7.50e−05) in a male with global developmental delay and epileptic encephalopathy (Fig. 3A).