GCH1基因突变致多巴反应性肌张力不全一例

多巴反应性肌张力不全（DRD）是一种常染色体显性或隐性遗传运动障碍疾病,病理特征为黑质纹状体多巴胺含量减少,主要表现为儿童期肌张力障碍, 小剂量左旋多巴可以改善症状。三磷酸鸟苷环化水解酶1（GCH1）基因是其致病基因之一。该文报道1例GCH1基因突变所致的DRD患儿,其以步态异常为主诉,行走时出现肌张力不全姿势,症状晨轻暮重,经基因检测证实其GCH1基因出现杂合性突变。接受小剂量左旋多巴治疗后患儿神经系统体征基本消失,于小儿神经科门诊随诊2年,运动功能良好。临床上对于病因不明的肌张力障碍患儿, 需警惕DRD的可能, 尽早识别和治疗可明显改善预后,预防残疾的发生。

Dopa-responsive dystonia induced by GCH1 gene mutation: a case report

Dopa-responsive dystonia（DRD） is an autosomal dominant or recessive dyskinesia, which is pathologically characterized with reduced amount of dopamine in the substantia nigra and striatum. DRD is mainly manifested with dystonian in early childhood. Low-dose levodopa can mitigate relevant symptoms. Guanosine triphosphate cyclohydrolase I （GCH1） gene is the pathogenic gene of DRD. In this article, 1 child diagnosed with DRD induced by GCH1 gene mutation was reported. Gait abnormality was the chief complaint. The child showed dystonic posture when walking. These symptoms were mitigated in the morning and aggravated during night. Gene detection confirmed the incidence of heterozygous mutation of GCH1 gene. The neurological symptoms of this child were basically cured after low-dose levodopa therapy. During 2-year follow-up at Department of Pediatric Neurology, motor function was restored to normal. In clinical practice, the possibility of DRD should be considered for pediatric dystonia with unknown causes. Prompt diagnosis and treatment can significantly improve clinical prognosis and prevent the incidence of disability.