线粒体脑肌病,乳酸性酸中毒和中风样发作(MELAS)综合征是最著名的线粒体疾病之一,大多数病例归因于m.3243A>G。MELAS综合征患者通常在生命的头二十年中表现出广泛的,以神经系统表现为主要特征的多系统表型-中风样发作。然而,在儿科患者中观察到明显的表型变异性,造成临床挑战并延迟诊断。
对儿科MELAS综合征患者进行了文献综述,并对英国三级儿科神经病学中心进行了回顾性分析。
这个案例系列包括三个孩子。所有患者均出现癫痫发作,并且MRI变化不限于单个血管区域。血液异质差异很大,一个病人需要做肌肉活检.基于114例患者的文献回顾,平均发病年龄为8.1岁,癫痫发作是卒中样发作最常见的表现.在大多数情况下,除血液以外的组织中的异型人质病较高。
在有可疑神经系统症状的儿童中调查MELAS综合征的阈值应该较低。如果血液m.3243A>G分析为阴性,然而临床怀疑仍然很高,应考虑侵入性测试或进一步询问线粒体基因组。
Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome is one of the most well-known mitochondrial diseases, with most cases attributed to m.3243A>G. MELAS syndrome patients typically present in the first two decades of life with a broad, multi-systemic phenotype that predominantly features neurological manifestations--stroke-like episodes. However, marked phenotypic variability has been observed among paediatric patients, creating a clinical challenge and delaying diagnoses.
A literature
review of paediatric MELAS syndrome patients and a retrospective analysis in a UK tertiary paediatric neurology centre were performed.
Three children were included in this case series. All patients presented with seizures and had MRI changes not confined to a single vascular territory. Blood heteroplasmy varied considerably, and one patient required a muscle biopsy. Based on a literature
review of 114 patients, the mean age of presentation is 8.1 years and seizures are the most prevalent manifestation of stroke-like episodes. Heteroplasmy is higher in a tissue other than blood in most cases.
The threshold for investigating MELAS syndrome in children with suspicious neurological symptoms should be low. If blood m.3243A>G analysis is negative, yet clinical suspicion remains high, invasive testing or further interrogation of the mitochondrial genome should be considered.