FDXR变异致线粒体F-S病患儿1例的临床表型及基因变异分析

Analysis of clinical phenotype and genetic variants in a child with mitochondrial F-S disease due to variants of FDXR gene

目的分析1例疑似线粒体F-S病患儿的临床表型及基因型特征,明确其致病原因,为临床诊断提供依据。方法选取2020年11月5日于湖南省儿童医院神经内科就诊的1例线料体F-S病患儿为研究对象。对患儿进行全外显子组测序(WES),应用生物信息学分析筛选致病性变异,并对核心家系成员采用Sanger测序分析变异来源。结果基因检测发现患儿的FDXR基因存在c.310C>T(p.R104C)和c.235C>T(p.R79C)复合杂合变异,分别源自其父亲与母亲。经检索HGMD、PubMed、1000 Genomes及dbSNP等数据库,2个变异位点均为新变异。经不同生物学信息分析软件进行变异位点致病性预测,结果均提示有害。结论多系统受累时需警惕线粒体疾病,FDXR基因复合杂合变异可能为本例患儿的致病原因。上述发现丰富了FDXR基因致线粒体F-S病的变异谱,并提示全外显子组基因检测对线粒体F-S病诊断的辅助意义。

Objective To analyze the clinical phenotype and genetic variants of a child suspected for mitochondrial F-S disease.Methods A child with mitochondrial F-S disease who visited Department of Neurology,Hunan Provincial children′s Hospital on November 5,2020 was selected as research subject of this study.Clinical data of the child was collected.The child was subjected to whole exome sequencing(WES).Bioinformatics tools were used to analyze the pathogenic variants.Candidate variants were verified by Sanger sequencing of the child and her parents.Results WES revealed that the child has harbored compound heterozygous variants of the FDXR gene,namely c.310C>T(p.R104C)and c.235C>T(p.R79C),which were inherited from her father and mother,respectively.Neither variant has been reported in HGMD,PubMed,1000 Genomes,and dbSNP databases.Both of the variants have been suggested as deleterious according to the prediction results from different bioinformatics analysis software.Conclusion Mitochondrial diseases should be suspected for patients with multiple system involvement.The compound heterozygous variants of the FDXR gene probably underlay the disease in this child.Above finding has enriched the spectrum of FDXR gene mutations underlying mitochondrial F-S disease.WES can facilitate the diagnosis of mitochondrial F-S disease at the molecular level.