Objective To study the clinical characteristics, diagnosis, treatment and prognosis of a patient with childhood-onset rapid-onset dystonia Parkinsonism (RDP) caused by ATP1A3 gene mutation, and review the related literature. Methods The patient with RDP caused by ATP1A3 gene mutation was admitted to Hunan Children's Hospital in March 2019. The clinical and genetic data of this patient had been analyzed retrospectively, and related literature from PubMed, Wanfang databases and CNKI to date (up to December 2019) with "Rapid-onset dystonia-parkinsonism", "RDP", "DYT12" as key words were reviewed. Results The patient was 4 years and 9 months (March 2019) old when she had the attack of the disease. After a febricity, she suddenly acquired acute aphasia, dysphagia, and movement disorder with a clear asthenic (face > arm > leg) gradient of involvement. Rehabilitation therapy and supportive treatment made his movement disorder gradually recovered but aphasia and dysphagia. Gene analysis showed that the ATP1A3 gene c.2267G > A (p.R756H) site heterozygosity missense mutation existed in the patient. The mutation site was a pathogenic mutation of RDP, which had been reported in literature at home and abroad. The patient was treated with benzodiazepine and the effect was significant. At present, a total of 61 patients have been reported to date, and a total of 17 different mutations in ATP1A3 gene with RDP have been reported to date. The typical clinical phenotypes of RDP include the abrupt onset of dysarthria, dysphagia, limb dystonia with bradykinesia, among which bulbar paralysis was obvious and dystonia had an anatomical distribution clearly following a asthenic gradient (face > arm > leg). Conclusions The clinical characteristics of RDP are distinct, and ATP1A3 gene is its pathogenic gene. The analysis of the clinical characteristics and genetic characteristics of RDP will be conducive to the early diagnosis and treatment of RDP as well as the eugenics. [ABSTRACT FROM AUTHOR]