BACKGROUND Rapid-onset dystonia-parkinsonism (RDP) is a disease characterized by an abrupt onset of dystonia accompanied by signs of parkinsonism and prominent bulbar symptoms. CASE REPORT We describe a case of a female patient, born after normal delivery, but diagnosed with mild intellectual disability at age 7. She presented with an abrupt onset of upper limb dystonia and bradykinesia without tremor in parkinsonism, as well as dysarthria and dysphagia caused by prominent bulbar symptoms, at age 9. She had normal findings on brain magnetic resonance imaging, electroencephalography, and blood examination but was diagnosed with a psychogenic disorder. At age 10, she developed left lower limb paroxysmal stiffness with pain, and at 14, she was hospitalized due to lasting paroxysmal symptoms. Whole-exome sequencing was performed for this index case and her parents, and a de novo missense variant c.829G > A, p.Glu277Lys in ATP1A3 was identified. DISCUSSION This RDP case highlights a rare clinical feature of paroxysmal dystonia that affects the lower left limb and develops after the abrupt onset of permanent dystonia. Currently, there are only three reported RDP cases associated with the same missense mutation, and we summarized the clinical features of all cases including ours, such as onset of age, time for stable, RDP score, relapse and exacerbation. Various symptoms owing to ATP1A3 mutation could develop as ATP1A3-related neurological disorders beyond classical phenotypes such as alternating hemiplegia of childhood (AHC) or RDP. Although RDP is extremely rare during childhood, it is important to understand its clinical characteristics in children.

中文翻译：

---

伴有 ATP1A3 突变和左下肢阵发性肌张力障碍的快速发作性肌张力障碍-帕金森病

背景快速发作性肌张力障碍-帕金森综合征(RDP)是一种以突然发作的肌张力障碍为特征的疾病，伴有帕金森综合征的体征和突出的延髓症状。病例报告 我们描述了一例正常分娩后出生的女性患者，但在 7 岁时被诊断为轻度智力障碍。她突然出现上肢肌张力障碍和运动迟缓，但没有帕金森综合征的震颤，以及构音障碍和吞咽困难。 9 岁时出现明显的延髓症状。她的脑磁共振成像、脑电图和血液检查结果正常，但被诊断出患有心因性障碍。10 岁时，她出现左下肢阵发性僵硬伴疼痛，14 岁时因持续的阵发性症状住院。对该指示病例及其父母进行了全外显子组测序，并鉴定了 ATP1A3 中的一个 de novo 错义变异 c.829G > A，p.Glu277Lys。讨论 该 RDP 病例突出了阵发性肌张力障碍的罕见临床特征，它影响左下肢并在永久性肌张力障碍突然发作后发展。目前，仅有3例报告的RDP病例与相同的错义突变相关，我们总结了包括我们在内的所有病例的临床特征，如发病年龄、稳定时间、RDP评分、复发和恶化。由于 ATP1A3 突变导致的各种症状可能会发展为 ATP1A3 相关的神经系统疾病，而不是经典表型，例如儿童交替性偏瘫 (AHC) 或 RDP。虽然 RDP 在童年时期极为罕见，