Background Fragile X syndrome(FXS).caused by CGG-repeat expansion in FMR1 promoter,is one of the most common causes of mental retardation.Individuals with full mutation and premutation alleles have a high risk of psyc...Background Fragile X syndrome(FXS).caused by CGG-repeat expansion in FMR1 promoter,is one of the most common causes of mental retardation.Individuals with full mutation and premutation alleles have a high risk of psychophysiological disorder and of having affected offspring.Frequencies of FMR1 alleles in general newborns have been reported in Caucasians but have not been investigated in the large-scale population in the mainland of China.Methods The sizes of FMRI CGG-repeats were analyzed in 51,661 newborns(28,114 males and 23,547 females)and also in a cohort of 33 children diagnosed with developmental delay using GC-rich polymerase chain reaction(PCR)and triple repeat primed PCR.Results The frequency of CGG repeats>100 was 1/9371 in males and 1/5887 in females,and the frequency of CGG repeats>54 was 1/1561 in males and 1/1624 in females.FMRJ full mutation and premutation were identified in 27.27%of children who had Ages and Stages Questionnaire scores less than two standard deviations from the cutoff value.Conclusions Our study revealed the prevalence of FXS in China and improved the sample databases of FXS,suggesting that the prevalence of FXS in Chinese is higher than estimated previously and that FXS screening can be advised to high-risk families.展开更多
目的了解深圳地区孕前育龄妇女脆性X智力低下1(Fragile X Mental Retardation,FMR1)基因(CGG)n重复序列多态性分布特征,为本区脆性X综合征(Fragile X Syndrome,FXS)的预警和孕前筛查提供参考依据。方法收集2017年4月～2018年1月来深圳...目的了解深圳地区孕前育龄妇女脆性X智力低下1(Fragile X Mental Retardation,FMR1)基因(CGG)n重复序列多态性分布特征,为本区脆性X综合征(Fragile X Syndrome,FXS)的预警和孕前筛查提供参考依据。方法收集2017年4月～2018年1月来深圳市龙华区人民医院进行孕前检查的育龄妇女1035名,采用Amp1ideX^(TM) FMR1PCR及毛细管电泳技术对全血标本中FMR1基因(CGG)n重复序列及重复数进行检测,并对检测结果进行统计分析。结果 1035名孕前育龄妇女2070条X染色体中共检出23种不同等位基因,CGG重复数目的变异范围为n=17～63,FMRI基因中最常见的CGG重复数为n=28,占49.32%(1021/2070),其次为n=30和n=29,分别占29.56%(612/2070)和11.16%(231/2070),CGG重复数目n=28的检出频率明显高于n=30和n=29,差异有统计学意义(χ~2=2.6145～4.0352,P<0.05)。检出FMR1基因突变5例,突变率为0.24%(5/2070),其中前突变2例(n=63的1例,n=58的1例),占0.10%(2/2070);中间型3例(n=47的2例,n=51的1例),占0.14%(3/2070)。结论深圳地区孕前育龄妇女有一定的FMRI基因突变携带率,加强孕前育龄妇女FMR1筛查,对预防或降低遗传性智力低下并伴有自闭症患儿出生率具有重要意义。展开更多
基金supported by the Key Research and Development Program of Zhejiang Province(2017C03009 to Q.S.)the National Key Research and Development Program of China(2017YFC1001703 to Q.S.)Q.S.was also supported by the Fundamental Research Funds for the Central Universities(2014QNA6002).
文摘Background Fragile X syndrome(FXS).caused by CGG-repeat expansion in FMR1 promoter,is one of the most common causes of mental retardation.Individuals with full mutation and premutation alleles have a high risk of psychophysiological disorder and of having affected offspring.Frequencies of FMR1 alleles in general newborns have been reported in Caucasians but have not been investigated in the large-scale population in the mainland of China.Methods The sizes of FMRI CGG-repeats were analyzed in 51,661 newborns(28,114 males and 23,547 females)and also in a cohort of 33 children diagnosed with developmental delay using GC-rich polymerase chain reaction(PCR)and triple repeat primed PCR.Results The frequency of CGG repeats>100 was 1/9371 in males and 1/5887 in females,and the frequency of CGG repeats>54 was 1/1561 in males and 1/1624 in females.FMRJ full mutation and premutation were identified in 27.27%of children who had Ages and Stages Questionnaire scores less than two standard deviations from the cutoff value.Conclusions Our study revealed the prevalence of FXS in China and improved the sample databases of FXS,suggesting that the prevalence of FXS in Chinese is higher than estimated previously and that FXS screening can be advised to high-risk families.
文摘目的了解深圳地区孕前育龄妇女脆性X智力低下1(Fragile X Mental Retardation,FMR1)基因(CGG)n重复序列多态性分布特征,为本区脆性X综合征(Fragile X Syndrome,FXS)的预警和孕前筛查提供参考依据。方法收集2017年4月～2018年1月来深圳市龙华区人民医院进行孕前检查的育龄妇女1035名,采用Amp1ideX^(TM) FMR1PCR及毛细管电泳技术对全血标本中FMR1基因(CGG)n重复序列及重复数进行检测,并对检测结果进行统计分析。结果 1035名孕前育龄妇女2070条X染色体中共检出23种不同等位基因,CGG重复数目的变异范围为n=17～63,FMRI基因中最常见的CGG重复数为n=28,占49.32%(1021/2070),其次为n=30和n=29,分别占29.56%(612/2070)和11.16%(231/2070),CGG重复数目n=28的检出频率明显高于n=30和n=29,差异有统计学意义(χ~2=2.6145～4.0352,P<0.05)。检出FMR1基因突变5例,突变率为0.24%(5/2070),其中前突变2例(n=63的1例,n=58的1例),占0.10%(2/2070);中间型3例(n=47的2例,n=51的1例),占0.14%(3/2070)。结论深圳地区孕前育龄妇女有一定的FMRI基因突变携带率,加强孕前育龄妇女FMR1筛查,对预防或降低遗传性智力低下并伴有自闭症患儿出生率具有重要意义。
