ADARB1 and Global developmental delay: ADAR2 is essential for recoding of brain pre-mRNAs, modulating the function of glutamate and serotonin receptors through the recoding of the transcripts of their subunits.1 7 8 In fact, impaired ADAR2 editing causes early onset progressive epilepsy and premature death in mice.9 In humans, biallelic ADARB1 variants have been very recently associated with a severe developmental and epileptic encephalopathy (DEE) characterised by global developmental delay (DD), severe-to-profound intellectual disability (ID), microcephaly, epilepsy and limb spasticity.10