Fragile X (Fra (X)) syndrome is the most frequent cause of inherited mentalretardation, and it is associated with the fragile site at Xq27.3. In 1991, the FMR1(fragile X mental retardation 1) gene was cloned in the vi...Fragile X (Fra (X)) syndrome is the most frequent cause of inherited mentalretardation, and it is associated with the fragile site at Xq27.3. In 1991, the FMR1(fragile X mental retardation 1) gene was cloned in the vicinity of this site. The muationand abnormal expression of FMR1 are the direct causes of Fra(X) syndrome. The展开更多
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
基金Project supported by the State Education Commission and the National Natural Science Foundation of China.
文摘Fragile X (Fra (X)) syndrome is the most frequent cause of inherited mentalretardation, and it is associated with the fragile site at Xq27.3. In 1991, the FMR1(fragile X mental retardation 1) gene was cloned in the vicinity of this site. The muationand abnormal expression of FMR1 are the direct causes of Fra(X) syndrome. The
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.
