目的对1例临床疑诊3-甲基巴豆酰辅酶A羧化酶缺乏症(3-methylcrotonyl-coenzyme A carboxylase deficiency,MCCD)患儿及其父母进行基因变异分析,寻找该家系的致病变异,为临床诊断提供分子遗传学依据。方法抽提先证者及其父母的外周血基因...目的对1例临床疑诊3-甲基巴豆酰辅酶A羧化酶缺乏症(3-methylcrotonyl-coenzyme A carboxylase deficiency,MCCD)患儿及其父母进行基因变异分析,寻找该家系的致病变异,为临床诊断提供分子遗传学依据。方法抽提先证者及其父母的外周血基因组DNA,应用全外显子组基因测序技术对疑似为MCCD疾病的先证者进行致病基因筛查。根据高通量测序结果,对先证者及其父母进行变异位点的Sanger测序验证分析。应用计算机软件预测变异位点氨基酸进化保守性和变异可能导致的蛋白质结构和功能变化,分析变异位点的性质。结果Sanger测序结果显示先证者为MCCC2基因c.1342G>A(p.Gly448Ala)纯合错义变异,为未报道过的新变异。先证者母亲为c.1342G>A(p.Gly448Ala)杂合变异携带者,父亲未检测到该变异。用PolyPhen-2和Mutation Taster软件预测该变异为致病性,变异区域序列在不同物种间高度保守。根据美国医学遗传学与基因组学学会遗传变异分类标准与指南,MCCC2基因c.1342G>A(p.Gly448Ala)变异判定为可能致病性变异(PM2+PP2~PP5)。结论先证者MCCC2基因c.1342G>A(p.Gly448Ala)纯合错义变异是其分子发病机制,基因变异分析有助于明确临床诊断。展开更多
Next generation sequencing is currently a cornerstone of genetic testing in routine diagnostics,allowing for the detection of sequence variants with so far unprecedented large scale,mainly in genetically heterogenous ...Next generation sequencing is currently a cornerstone of genetic testing in routine diagnostics,allowing for the detection of sequence variants with so far unprecedented large scale,mainly in genetically heterogenous diseases,such as neurological disorders.It is a fast-moving field,where new wet enrichment protocols and bioinformatics tools are constantly being developed to overcome initial limitations.Despite the as yet undiscussed advantages,however,there are still some challenges in data analysis and the interpretation of variants.In this review,we address the current state of next generation sequencing diagnostic testing for inherited human disorders,particularly giving an overview of the available high-throughput sequencing approaches;including targeted,whole-exome and whole-genome sequencing;and discussing the main critical aspects of the bioinformatic process,from raw data analysis to molecular diagnosis.展开更多
Human genetic adaptation to high altitudes(>2500 m)has been extensively studied over the last few years,but few functional adaptive genetic variants have been identified,largely owing to the lack of deep-genome seq...Human genetic adaptation to high altitudes(>2500 m)has been extensively studied over the last few years,but few functional adaptive genetic variants have been identified,largely owing to the lack of deep-genome sequencing data available to previous studies.Here,w e build a list of putative adaptive variants,including 63 missense,7 loss-of-function;1,298 evolutionarily conserved variants and 509 expression quantitative traits loci.Notably,the top signal of selection is located in TMEM 247,a transmembrane protein-coding gene.The Tibetan version of TMEM 247 harbors one high-frequency(76.3%)missense variant,rsl 16983452(c.248C>T;p.Ala83Val);with the T allele derived from archaic ancestry and carried by>94%of Tibetans but absent or in low frequencies(<3%)in non-Tibetan populations.The rsl 16983452-T is strongly and positively correlated with altitude and significantly associated with reduced hemoglobin concentration(p=5.78×10^-5),red blood cell count(p=5.72×10^-7)and hematocrit(p=2.57×10^-6).In particular,TMEM247-rs 116983452 shows greater effect size and better predicts the phenotypic outcome than any E P A S1 variants in association with adaptive traits in Tibetans.Modeling the interaction between TM£M247-rsl 16983452 and EPAS1 variants indicates weak but statistically significant epistatic effects.Our results support that multiple variants may jointly deliver the fitness of the Tibetans on the plateau,where a complex model is needed to elucidate the adaptive evolution mechanism.展开更多
文摘目的对1例临床疑诊3-甲基巴豆酰辅酶A羧化酶缺乏症(3-methylcrotonyl-coenzyme A carboxylase deficiency,MCCD)患儿及其父母进行基因变异分析,寻找该家系的致病变异,为临床诊断提供分子遗传学依据。方法抽提先证者及其父母的外周血基因组DNA,应用全外显子组基因测序技术对疑似为MCCD疾病的先证者进行致病基因筛查。根据高通量测序结果,对先证者及其父母进行变异位点的Sanger测序验证分析。应用计算机软件预测变异位点氨基酸进化保守性和变异可能导致的蛋白质结构和功能变化,分析变异位点的性质。结果Sanger测序结果显示先证者为MCCC2基因c.1342G>A(p.Gly448Ala)纯合错义变异,为未报道过的新变异。先证者母亲为c.1342G>A(p.Gly448Ala)杂合变异携带者,父亲未检测到该变异。用PolyPhen-2和Mutation Taster软件预测该变异为致病性,变异区域序列在不同物种间高度保守。根据美国医学遗传学与基因组学学会遗传变异分类标准与指南,MCCC2基因c.1342G>A(p.Gly448Ala)变异判定为可能致病性变异(PM2+PP2~PP5)。结论先证者MCCC2基因c.1342G>A(p.Gly448Ala)纯合错义变异是其分子发病机制,基因变异分析有助于明确临床诊断。
文摘Next generation sequencing is currently a cornerstone of genetic testing in routine diagnostics,allowing for the detection of sequence variants with so far unprecedented large scale,mainly in genetically heterogenous diseases,such as neurological disorders.It is a fast-moving field,where new wet enrichment protocols and bioinformatics tools are constantly being developed to overcome initial limitations.Despite the as yet undiscussed advantages,however,there are still some challenges in data analysis and the interpretation of variants.In this review,we address the current state of next generation sequencing diagnostic testing for inherited human disorders,particularly giving an overview of the available high-throughput sequencing approaches;including targeted,whole-exome and whole-genome sequencing;and discussing the main critical aspects of the bioinformatic process,from raw data analysis to molecular diagnosis.
基金supported by the Strategic Priority Research Program(XDB13040100 to S.X.)Key Research Program of Frontier Sciences(QYZDJ-SSW-SYS009 to S.X.)of the Chinese Academy of Sciences(CAS)+18 种基金the National Natural Science Foundation of China(NSFC)(91731303,31525014,31961130380 and 31771388 to S.X.31501011 to Y.L.31771389 to Y.Y.(Yuan Yuan)81522014 to Z.J.31871256and 31601046 to H.L.31460286,31660307 and 31260252to L.K.)the Program of Shanghai Academic Research Leader(16XD1404700 to S.X.)the UK Royal Society-Newton Advanced Fellowship(NAF\R1\191094 to S.X.)the National Key Research and Development Program(2016YFC0906403 to S.X.2017YFA0105300 to Z.J.2016YFF0202301 to Y.Y.(Yajun Yang))Shanghai Municipal Science and Technology Major Project(2017SHZDZX01 to S.X.)Science and Technology Commission of Shanghai Municipality(STCSM,19YF1455200to L.D.16YF1413900 to H.L.)NSFC Research Fund for International Young Scientists(31850410477 to A.K.)CAS President’s International Fellowship for Postdoctoral Researchers(2016 PB036 to A.K.)S.X.is Max-Planck Independent Research Group Leader and member of CAS Youth Innovation Promotion Associationsupported by the National Program for Top-notch Young Innovative Talents of the ‘Wanren Jihua’ Projectthe UK Royal Society-Newton Mobility Grants(IE160943 to S.X.).
文摘Human genetic adaptation to high altitudes(>2500 m)has been extensively studied over the last few years,but few functional adaptive genetic variants have been identified,largely owing to the lack of deep-genome sequencing data available to previous studies.Here,w e build a list of putative adaptive variants,including 63 missense,7 loss-of-function;1,298 evolutionarily conserved variants and 509 expression quantitative traits loci.Notably,the top signal of selection is located in TMEM 247,a transmembrane protein-coding gene.The Tibetan version of TMEM 247 harbors one high-frequency(76.3%)missense variant,rsl 16983452(c.248C>T;p.Ala83Val);with the T allele derived from archaic ancestry and carried by>94%of Tibetans but absent or in low frequencies(<3%)in non-Tibetan populations.The rsl 16983452-T is strongly and positively correlated with altitude and significantly associated with reduced hemoglobin concentration(p=5.78×10^-5),red blood cell count(p=5.72×10^-7)and hematocrit(p=2.57×10^-6).In particular,TMEM247-rs 116983452 shows greater effect size and better predicts the phenotypic outcome than any E P A S1 variants in association with adaptive traits in Tibetans.Modeling the interaction between TM£M247-rsl 16983452 and EPAS1 variants indicates weak but statistically significant epistatic effects.Our results support that multiple variants may jointly deliver the fitness of the Tibetans on the plateau,where a complex model is needed to elucidate the adaptive evolution mechanism.