GNAO1 and Global developmental delay: GNAO1 encodes the α‐subunit of a heterotrimeric guanine nucleotide‐binding protein (Gαo), which is widely expressed in the central nervous system, playing an important role in signal transduction through AMPc metabolism in the striatum.2, 5, 6 As the number of reports increased, it became evident that GNAO1‐related encephalopathies encompass a continuous spectrum of neurological syndromes featuring variable association of movement disorders, psychomotor delay, intellectual disability (ID), and different types of epilepsy.2, 7GNAO1‐related movement disorder usually starts in infancy.