Monarch Disease Ontology identifier MONDO_1060177 (developmental and epileptic encephalopathy 119) is a developmental and epileptic encephalopathy caused by the variants in the RNU2-2 gene, in which most reported variants are de novo. It is characterized by global developmental delay, hypotonia, impaired intellectual development, microcephaly, autistic behavior, and characteristically complex seizures. Also known as: DEE119, RNU2-2 developmental and epileptic encephalopathy, RNU2-2 syndrome.