Ma Yan-Yan, Li Xi-Yuan, Li Zhi-Qin, Song Ji-Qing, Hou Jing, Li Jian-Hua, Sun Li, Jiang Jun, Yang Yan-Ling
Department of Pediatrics, Qinghai University Affiliated Hospital, Xining Department of Pediatrics, Peking University First Hospital, Beijing Department of Oncology, Qinghai University Affiliated Hospital, Xining, China.
Medicine (Baltimore). 2018 Aug;97(32):e11606. doi: 10.1097/MD.0000000000011606.
Mitochondrial respiratory chain complex I deficiency is one of common mitochondrial disorders. However, the information is relatively little about the features of Chinese patients. In this study, the clinical, biological, and genetic analyses were performed in the children with respiratory chain complex I deficiency, in order to further understand the characteristics of the disease.Over a 3-year period, 67 patients (37 boys, 30 girls), presenting with unexplained multisystemic symptoms and signs were recruited. Clinical and laboratory data of the patients were summarized. Spectrophotometric assay was used for the analysis of mitochondrial complex I-V enzyme activity in peripheral leukocytes. The entire mitochondrial DNA (mtDNA) sequence was analysed for patients and their mothers.The children with respiratory chain complex I deficiency presented with multisystem dysfunction. Onset occurred before the third year of life in 96.9% patients without mtDNA mutation. Onset occurred before the third year of life in 76.5% of patients with mtDNA mutation (P = .03). About 51.5% of patients without mtDNA mutation had weakness, which is higher than 24% patients with mtDNA mutation (P = .02). Isolated complex I deficiency and combined complex I deficiency were found in 45 and 22 patients, respectively. The prevalence of isolated complex I deficiency was higher in the patients with mtDNA mutations (79.4%) than in the patients without mtDNA mutations (54.5%).Patients with nuclear DNA mutations are more likely to develop early onset in mitochondrial respiratory chain complex I deficiency. The patients with complex I deficiency of peripheral leukocytes may be more likely to be caused by mtDNA mutation.
线粒体呼吸链复合体I缺陷是常见的线粒体疾病之一。然而，关于中国患者的特征信息相对较少。在本研究中，对患有呼吸链复合体I缺陷的儿童进行了临床、生物学和遗传学分析，以进一步了解该疾病的特点。
在3年的时间里，招募了67例出现不明原因多系统症状和体征的患者（37名男孩，30名女孩）。总结了患者的临床和实验室数据。采用分光光度法分析外周血白细胞中线粒体复合体I-V酶活性。对患者及其母亲进行了整个线粒体DNA（mtDNA）序列分析。
患有呼吸链复合体I缺陷的儿童表现出多系统功能障碍。96.9%无mtDNA突变的患者在3岁前发病。76.5%有mtDNA突变的患者在3岁前发病（P = 0.03）。约51.5%无mtDNA突变的患者有肌无力，高于24%有mtDNA突变的患者（P = 0.02）。分别在45例和22例患者中发现了孤立性复合体I缺陷和复合性复合体I缺陷。孤立性复合体I缺陷在有mtDNA突变的患者中的患病率（79.4%）高于无mtDNA突变的患者（54.5%）。
线粒体呼吸链复合体I缺陷中，核DNA突变的患者更易早发疾病。外周血白细胞复合体I缺陷的患者可能更易由mtDNA突变引起。
