氨酰基-tRNA合成酶基因变异10例分析

目的研究氨酰基-tRNA合成酶(ARS)缺陷相关疾病的临床特征。方法回顾性分析2016年1月至2019年10月通过二代测序诊断的10例ARS基因变异患儿的临床资料及基因突变类型。结果 10例ARS基因变异患儿中,起病年龄为0~9岁,首发症状多为抽搐(7例)。临床表现为共济失调为主而智力轻度落后或正常,伴或不伴有癫痫(4例);或儿童期起病的癫痫,后出现发育倒退(2例);也可表现为新生儿期起病,严重癫痫脑病,出现肌阵挛、全面强直及痉挛发作(4例),伴有严重发育落后(3例)、喂养困难(2例)、听力损害(1例)等。10例患儿中,共检测出5种基因突变,包括AARS2(c.331G>C、c.2682+5G>A、c.2164C>T、c.761G>A,均为新突变)3例,DARS2(c.228-16C>A、c.536G>A,均为已报道突变)2例,CARS2(c.1036C>T、c.323T>G,均为新突变)1例,RARS2(c.1210A>G、c.622C>T,均为新突变)1例,AARS(c.1901T>A、c.229C>T、c.244C>T、c.961G>C、Chr16:70298860-70316687del、c.2248C>T,均为新突变)3例。结论 ARS基因缺陷相关疾病临床表型异质性高。该研究共发现5种ARS基因的14个未报道的变异,丰富了ARS缺陷相关疾病的临床表型及基因型。

Mutations in aminoacyl-tRNA synthetase genes: an analysis of 10 cases

Objective To study the clinical features of the diseases associated with aminoacyl-tRNA synthetases (ARS) deficiency. Methods A retrospective analysis was performed of the clinical and gene mutation data of 10 children who were diagnosed with ARS gene mutations, based on next-generation sequencing from January 2016 to October 2019. Results The age of onset ranged from 0 to 9 years among the 10 children. Convulsion was the most common initial symptom (7 children). Clinical manifestations included ataxia and normal or mildly retarded intellectual development (with or without epilepsy; n=4) and onset of epilepsy in childhood with developmental regression later (n=2). Some children experienced disease onset in the neonatal period and had severe epileptic encephalopathy, with myoclonus, generalized tonic-clonic seizure, and convulsive seizure (n=4); 3 had severe delayed development, 2 had feeding difficulty, and 1 had hearing impairment. Mutations were found in five genes:3 had novel mutations in the AARS2 gene (c.331G > C, c.2682+5G > A, c.2164C > T, and c.761G > A), 2 had known mutations in the DARS2 gene (c.228-16C > A and c.536G > A), 1 had novel mutations in the CARS2 gene (c.1036C > T and c.323T > G), 1 had novel mutations in the RARS2 gene (c.1210A > G and c.622C > T), and 3 had novel mutations in the AARS gene (c.1901T > A, c.229C > T, c.244C > T, c.961G > C, c.2248C > T, and Chr16:70298860-70316687del). Conclusions A high heterogeneity is observed in the clinical phenotypes of the diseases associated with the ARS deficiency. A total of 14 novel mutations in 5 genes are reported in this study, which enriches the clinical phenotypes and genotypes of the diseases associated with ARS deficiency.