An 18-year-old man had episodes of severe generalised dystonia, from aged 7 months and becoming progressively more frequent. He also had gradually developed interictal limb dystonia. He was initially diagnosed with paroxysmal kinesigenic dyskinesia but he did not improve with several medications. A levodopa trial led to levodopa-induced dyskinetic movements. However, a lower titration of 25 mg of levodopa two times per day substantially improved his motor features and quality of life. Laboratory investigations and MR scans of the brain were unremarkable. Whole-exome sequencing identified a pathogenic variant in the ATP1A3 gene. The ATP1A3 -spectrum disorders include non-classical phenotypes such as paroxysmal dystonic attacks. A response to dopamine response is unusual in these disorders. This case highlights the importance of levodopa trials in early-onset dystonia cases. All data relevant to the study are included in the article or uploaded as online supplemental information.

中文翻译：

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与 ATP1A3 基因变异相关的多巴反应性肌张力障碍和阵发性肌张力障碍发作

一名 18 岁男性从 7 个月起就出现严重全身性肌张力障碍，且病情逐渐加重。他还逐渐出现了发作间期肢体肌张力障碍。他最初被诊断患有阵发性运动源性运动障碍，但服用多种药物后病情没有改善。一项左旋多巴试验导致左旋多巴引起的运动障碍。然而，每天两次 25 毫克左旋多巴的较低剂量大大改善了他的运动功能和生活质量。实验室检查和大脑磁共振扫描没有发现异常。全外显子组测序发现了 ATP1A3 基因的致病性变异。ATP1A3谱系疾病包括非经典表型，例如阵发性肌张力障碍发作。在这些疾病中，对多巴胺反应的反应是不寻常的。该病例凸显了左旋多巴试验在早发性肌张力障碍病例中的重要性。与研究相关的所有数据都包含在文章中或作为在线补充信息上传。