RRM2B gene mutation-related diseases can be divided into four types according to genetic pattern and clinical phenotype of mitochondrial DNA depletion syndrome 8A (MTDPS8A), mitochondrial DNA depletion syndrome 8B (MTDPS8B), rod-cone dystrophy, sensorineural deafness, and fanconi-type renal dysfunction (RCDFRD), progressive external ophthalmoplegia with mitochondrial and deletions, autosomal dominant 5 (PEOA5). Among them, MTDPS8A and MTDPS8B are both mitochondrial DNA depletion syndromes with the same genetic pattern, and the clinical phenotypes are complex and heterogeneous in the early stage, making it difficult to identify them. This paper systematically reviewed and analyzed the clinical characteristics, genetic test results, diagnosis and treatment process and other case data of two children diagnosed with MTDPS8A and MTDPS8B, and reviewed relevant literature to summarize the genetic characteristics of these two types, so as to provide diagnostic ideas for future suspected cases and further improve the clinical diagnosis rate of RRM2B mutation-related mitochondrial encephalomyopathy, which also helps to assess the prognosis.

RRM2B基因突变相关疾病根据遗传方式和临床表型可分为线粒体DNA耗竭综合征8A型（MTDPS8A），线粒体DNA耗竭综合征8B型（MTDPS8B），锥杆营养不良、感音神经性耳聋和范可尼型肾功能障碍（RCDFRD），常染色体显性进行性眼外肌麻痹伴线粒体DNA缺失5型（PEOA5）这4种类型。其中MTDPS8A、MTDPS8B均属于线粒体DNA耗竭综合征，遗传方式相同，在疾病早期临床表型复杂且具有异质性，难以鉴别。本文通过系统回顾分析2例分别确诊MTDPS8A、MTDPS8B患儿的临床特点、基因检测结果、诊治经过等病例资料，并复习相关文献来总结这两型的遗传学特点，为今后遇到疑似病例提供诊断思路，进一步提高RRM2B基因突变相关线粒体脑肌病的临床诊断率，也有助于评估预后情况。