Abstract: Objective　To investigate the clinical characteristics and genotypic-phenotypic correlation of G203R variation in GNAO1 gene. Methods　The clinical data of G203R variation in GNAO1 gene in a child was retrospectively analyzed. In addition, "GNAO1G203R" was used as the search term to retrieve and review the literature in CNKI, Wanfang Database and PubMed, etc. Results　A 7-month-old male child presented with recurrent seizures, twist, chorea, mouth opening, rictus and tongue clicking, growth retardation and hypotonia. The G203R mutation of GNAO1 gene was detected by whole exon sequencing. After treatment with the combination of antiepileptic drugs, epilepsy had been controlled in the child, but he still had the repeated twisting, chorea and oral and facial movement. The literature retrieved 6 cases of G203R mutation in GNAO1 gene and they had similar clinical manifestations. Conclusion　The main clinical features of G203R mutation in GNAO1 gene are epileptic encephalopathy, dyskinesia and growth retardation.

Key words: GNAO1 gene;　G203R mutation;　epilepsy;　movement disorder