Mutation Screening Of Pathogenic Genes For Premature Ovarian Insufficiency In A Consanguineous Family And A Preliminary Functional Study Of The Novel Homozygous Mutation

ObjectivePremature ovarian insufficiency?POI?refers to loss of ovarian activity before the age of 40 years.The pathogenesis of POI is still unclear,strong genetic component has been suggested in POI pathophysiology.The aim of this study was to explore the candidate pathogenic gene in a POI proband from consanguineous marriage family,and detect the potential effects of mutation on cellular energy metabolism of cells.MethodsParticipants were recruited from POI patients diagnosed at the Reproductive Center of the First Affiliated Hospital of Anhui Medical University.Whole exome sequencing?WES?was performed for the proband.Variation revealed by WES sequencing was validated by Sanger sequencing in her family.Sequencing data were combined with those of other sporadic cases listed in public databases to identify the causative gene.Metabolic analyzes were performed using Seahorse XFe96 Analyzers?Agilent Technologies,USA?around the novel mutation of alanyl-t RNA synthetase 2?AARS2?to obtain measurements of the fundamental parameters oxygen consumption?OCR?,further derive the value of ATP production and extracellular acidification rate?ECAR?.The differences in measurements of energy metabolism between wild-type and mutation were analyzed and compared.ResultsA novel alanyl-t RNA synthetase 2?AARS2?homozygous mutation?NM₀20745: exon2: c.337G>C: p.G113R?is identified by WES in a consanguineous Chinese family,located in the aminoacylation region of AARS2.The mutation was highly conserved among species and predicted to be a disorder cause.In mitochondrial stress tests,which used to assess mitochondrial function by measuring mitochondrial respiration,the mutation group?3.58±0.46fmol/min/cell?is significantly lower than the wild-type group?6.96±1.56fmol/min/cell?in ATP production.ConclusionOur study is the first to report a homozygous pathogenic mutation of AARS2 in POI.This mutation might result in incorrect aminoacylation of t RNA,affecting mitochondrial translation and causes OXPHOS?oxidative phosphorylation?defects further can lead to altered ovarian cellular physiology and manifest in POI.