BACKGROUND Mitochondrial DNA copy number is a potential biomarker for mitochondrial dysfunction and is involved in a variety of disease states including autism, neurodegenerative diseases and traumatic brain injury, but few studies on mitochondrial DNA copy number in cerebral palsy have been reported. Therefore, this study aims to investigate the role of mitochondrial DNA copy number in children with cerebral palsy. METHODS A total of 104 children with cerebral palsy and 78 typically developing children were enrolled in this study. All children with cerebral palsy were diagnosed according to clinical criteria and furtherly divided into clinical subtypes. Mitochondrial DNA copy number was quantified by droplet digital PCR. RESULTS We observed a significant reduction in mitochondrial DNA copy number from children with cerebral palsy comparing to healthy controls (216.76 ± 71.39 vs 359.66 ± 72.78, p < 0.001). An upward trend in mitochondrial DNA copy number alteration with the increase of age was found in healthy controls rather than in children with cerebral palsy. In addition, the mitochondrial DNA copy number in children with spastic hemiplegia was higher than that in children with spastic quadriplegia (152.27 ± 49.78 vs 90.64 ± 21.55, p = 0.001). CONCLUSIONS Our results suggest that on the basis of accurate quantification by droplet digital PCR, the declined mitochondrial DNA copy number probably has certain implications for mitochondrial dysfunction in children with cerebral palsy, which provides a new clue for the investigation on the molecular mechanism and clinical characteristics of cerebral palsy.

中文翻译：

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小儿数字麻痹定量脑瘫患儿线粒体DNA拷贝数减少。

背景技术线粒体DNA拷贝数是线粒体功能障碍的潜在生物标志物，并涉及多种疾病状态，包括自闭症，神经退行性疾病和外伤性脑损伤，但是关于脑瘫中线粒体DNA拷贝数的研究很少。因此，本研究旨在探讨线粒体DNA拷贝数在脑瘫患儿中的作用。方法本研究共纳入104名脑瘫儿童和78名典型发育中的儿童。根据临床标准诊断所有脑瘫患儿，并进一步分为临床亚型。线粒体DNA拷贝数通过液滴数字PCR定量。结果与健康对照组相比，我们发现脑瘫患儿的线粒体DNA拷贝数明显减少（216.76±71.39 vs 359.66±72.78，p <0.001）。在健康对照组而不是脑瘫患儿中，线粒体DNA拷贝数随年龄的增加而增加。此外，痉挛性偏瘫儿童的线粒体DNA拷贝数高于痉挛性四肢瘫痪的儿童（152.27±49.78 vs 90.64±21.55，p = 0.001）。结论我们的研究结果表明，在通过液滴数字PCR进行准确定量的基础上，线粒体DNA拷贝数下降可能对脑瘫患儿的线粒体功能障碍有一定的影响，