Background: Fragile X Syndrome (FXS) is the most common cause of inherited mental retardation. The absence of Fragile X Mental Retardation (FMRP) in Fragile X syndrome changes other proteins. Objective: To detect changes of glycoprotein in human serum of Fragile X syndrome. Subject and methods: Affinity chromatography with lectin concanavalin A (ConA) used to receive glycoprotein. The collected glycoprotein was then separated using 2-D electrophoresis. The protein spots were further excised, trypsin digested, and analyzed by nano LC couple with ESI-MS/MS and identified by MASCOT v1.8 software. Results and conclusion: 5 glycoproteins showed the different expression levels in the serum of Fragile X syndrome. Haptoglobin, Ig-J were increased and ceruloplasmin, transferring, Ig kappa were decreased. Using affinity chromatography with lectin concanavalin A (ConA), glycoprotein was received and divided on 2 ways electrokinetic chromatography. The mixture protein was identified with a reliability of 99.5% by 2 ways liquid chromatography combined with continuous spectrum mass.
Fragile X syndrome ; Fragile X Mental Retardation ; proteomics

Background: Fragile X Syndrome (FXS) is the second cause of Mental Retardation (MR) and the first cause of familiar MR. This syndrome affects up to 1/4000 men and 1/8000 women. X syndrome is often diagnosed by molecular biology technique such as RCR and Southern blot. Until now there is no study on FXS in Vietnam. Objectives: This study is aimed at: (1) Determine FXS among children with MR by technique of molecular biology. (2) Determine the mutation of FMR1 gen in families having children with FXS. Subject and Method: 214 children between 6 and 16 years of age (136 male and 78 female) with MR were analyzed FMR1 gen by PCR and Southern blot techniques. Families of children with FXS were also analyzed. Result and conclusion: This is the first study on FXS using the techniques of molecular biology in Vietnam. Identified 3 children with FXS, accounting for 1.4% of MR. Children with FXS and members with full mutation and premutation were found.
Fragile X syndrome ; FMR1 gene ; Mental retardation

Fragile X mental retardation 1 is the gene underlying fragile X syndrome (FXS). Its product, fragile X mental retardation protein, is closely involved with development of brain and neurons. PCR and Southern blotting have been the major methods for laboratory diagnosis of FXS. In this article, the progress in the molecular diagnosis of FXS is reviewed.
Fragile X Mental Retardation Protein ; genetics ; Fragile X Syndrome ; diagnosis ; genetics ; Humans ; Pathology, Molecular ; methods

OBJECTIVETo establish a method of methylation-sensitive restriction enzymes based quantitative PCR (MSRE-qPCR) for analysis of CpG island DNA of FMR1 gene, and to assess its value for molecular diagnosis of fragile X syndrome.

METHODSThirty boys with mental retardation and abnormal repeats of 5'(CGG)n in the FMR1 gene and 20 mothers were analyzed by conventional PCR screening. Eag I was used to digest genomic DNA, and qPCR was performed to amplify CpG island in the FMR1 gene using both undigested and digested templates. Raw Ct values were obtained through quantitative PCR amplification. The degree of CpG island methylation was calculated by 2 - U+0394 U+0394 Ct. The result of MSRE-qPCR was verified by Southern blotting. 30 healthy females and 30 healthy males were used as controls to optimize the established MSRE-qPCR method.

RESULTSThe ranges of 2 - U+0394 U+0394 Ct value for normal methylation, partial methylation and full methylation were determined. Among the 30 patients, 3 were found to have partial methylation of CpG island of the FMR1 gene, and 27 were found to have full methylation (3/30 results were verified by Southern blotting). Only 7 mothers were found abnormal methylation of CpG island of FMR1 gene, whilst the remaining 13 mothers were normal.

CONCLUSIONMSRE-qPCR is a quick and reliable method for quantitative analysis of CpG island methylation status in FMR1 gene, which may provide a new strategy for the diagnosis of fragile X syndrome.

CpG Islands ; DNA Methylation ; Female ; Fragile X Mental Retardation Protein ; genetics ; Fragile X Syndrome ; diagnosis ; genetics ; Humans ; Male ; Sex Factors

Fragile X-associated tremor/ataxia syndrome(FXTAS) is a neurodegenerative disease caused by FMR1 gene permutation(PM). The main clinical manifestations are intention tremor and/or ataxia, and the pathogenesis was related to RNA toxicity. In this paper, the research progress of clinical manifestatios, pathological characteristics, epidemiology and molecular mechanisms will be reviewed.
Ataxia ; genetics ; Female ; Fragile X Mental Retardation Protein ; genetics ; Fragile X Syndrome ; complications ; diagnosis ; genetics ; pathology ; Humans ; Male ; Tremor ; genetics

OBJECTIVETo analyze (CGG)n repeats sequence and AGG interspersion correlated with unstable expansion of FMR1 gene in a general Chinese population.

METHODSAmplideX FMR1 PCR Kit was used to amplify 380 X chromosomes from randomly selected 176 males and 102 females, 11 permutation carriers and 10 full mutation patients have served as controls. Results of capillary electrophoresis were analyzed with GeneMapper software Version 4.0. SPSS 11.0 software was used for statistical analysis.

RESULTSThe ratio of heterozygous females was 64.70%. The number of alleles in general males and females was 15 and 14, the classes of AGG pattern was 26 and 27, respectively. The range of alleles was between 17 to 45 CGG repeats in males and 21 to 44 CGG repeats in females, and 1 male was identified as gray zone carrier. The most frequent allele was 29 CGG repeats, which was followed by 30 and 36 repeats, while 28 CGG repeats were absent. The most common AGG pattern was 9A9A9, 99.21% of the population was detected with different forms and numbers of AGG interruption, and 6A interruption pattern was found in 10.02% samples especially in individuals with more CGG repeats. However, 57.58% of control samples had no AGG interruption, and none of the controls had 6A interruption pattern. No significant difference was observed in allele frequent distribution of (CGG)n repeats and AGG interspersion patterns between the males and females (P > 0.05), and AGGs was significantly different between general population and controls (P < 0.05).

CONCLUSIONAGGs and AGG pattern may have important roles in maintaining (CGG)n stability in general population of China, 9A9A6A9 may be a special pattern for preventing (CGG)n unstable expansion in Asian populations.

Adolescent ; Adult ; Alleles ; Female ; Fragile X Mental Retardation Protein ; genetics ; Fragile X Syndrome ; genetics ; Humans ; Male ; Middle Aged ; Trinucleotide Repeats

OBJECTIVE: To determine the CGG repeat number and methylation status of FMR1 gene for fetuses whose mothers have carried a FMR1 mutation. METHODS: For 30 pregnant women, the fetal CGG repeat number was determined with a GC-rich PCR system by using chorionic villus, amniotic fluid or umbilical blood samples. The methylation status of the FMR1 gene was confirmed with Southern blotting. RESULTS: In total 30 prenatal diagnoses were performed for 29 carriers of FMR1 gene mutations and 1 with FMR1 gene deletion mosaicism. Three fetuses were found to carry premutations, 9 were with full mutations and 1 with mosaicism of premutation and full mutations. Eighteen fetuses were normal. CONCLUSION Considering the genetic complexity of Fragile X syndrome (FXS), single method may not suffice accurate determination of their genetic status. The pitfalls and technical limitations of protocols requires adoption of personalized strategy for its prenatal diagnosis.
Female ; Fragile X Mental Retardation Protein ; genetics ; Fragile X Syndrome ; diagnosis ; Heterozygote ; Humans ; Mutation ; Pregnancy ; Prenatal Diagnosis

OBJECTIVE: To analyze the (CGG)n repeats of FMR1 gene among patients with unexplained mental retardation. METHODS: For 201 patients with unexplained mental retardation, the (CGG)n repeats of the FMR1 gene were analyzed by PCR and FragilEase RESULTS: For the 201 patients with unexplained mental retardation, 15 were identified with full mutations of the FMR1 gene. The prevalence of fragile X syndrome (FXS) in patients with unexplained mental retardation was determined as 7.5% (15/201). Prenatal diagnosis was provided for 6 pregnant women with pre- or full mutations. Analysis revealed that women with mental retardation and full FMR1 mutations exhibited a skewed XCI pattern with primary expression of the X chromosome carrying the mutant allele. CONCLUSION FXS has a high incidence among patients with unexplained mental retardation. Analysis of FMR1 gene (CGG)n repeats in patients with unexplained mental retardation can facilitate genetic counseling and prenatal diagnosis for their families. FMR1 gene (CGG)n repeats screening should be recommended for patients with unexplained mental retardation.
Female ; Fragile X Mental Retardation Protein/genetics* ; Fragile X Syndrome/genetics* ; Humans ; Intellectual Disability/genetics* ; Mutation ; Pregnancy ; Prenatal Diagnosis

Many people affected by fragile X syndrome (FXS) and autism spectrum disorders have sensory processing deficits, such as hypersensitivity to auditory, tactile, and visual stimuli. Like FXS in humans, loss of Fmr1 in rodents also cause sensory, behavioral, and cognitive deficits. However, the neural mechanisms underlying sensory impairment, especially vision impairment, remain unclear. It remains elusive whether the visual processing deficits originate from corrupted inputs, impaired perception in the primary sensory cortex, or altered integration in the higher cortex, and there is no effective treatment. In this study, we used a genetic knockout mouse model (Fmr1^KO), in vivo imaging, and behavioral measurements to show that the loss of Fmr1 impaired signal processing in the primary visual cortex (V1). Specifically, Fmr1^KO mice showed enhanced responses to low-intensity stimuli but normal responses to high-intensity stimuli. This abnormality was accompanied by enhancements in local network connectivity in V1 microcircuits and increased dendritic complexity of V1 neurons. These effects were ameliorated by the acute application of GABA_A receptor activators, which enhanced the activity of inhibitory neurons, or by reintroducing Fmr1 gene expression in knockout V1 neurons in both juvenile and young-adult mice. Overall, V1 plays an important role in the visual abnormalities of Fmr1^KO mice and it could be possible to rescue the sensory disturbances in developed FXS and autism patients.
Animals ; Disease Models, Animal ; Fragile X Mental Retardation Protein/metabolism* ; Fragile X Syndrome/metabolism* ; Humans ; Mice ; Mice, Knockout ; Neurons/metabolism*

Fragile X syndrome (FXS) is the most common monogenic form of inherited intellectual disability and autism spectrum disorder (ASD). More than 99% of individuals with FXS are caused by the unstable expansion of CGG repeats located within the 5'-untranslated region of the FMR1 gene. The clinical features of FXS include various degrees of cognitive deficit, physical, behavioral and psychiatric problems. Early treatment and prevention from having further affected children can be guided by molecular genetic testing of the FMR1 gene. The following guideline has combined the relevant research, guidelines and consensus worldwide, and summarized the genetic knowledge and clinical treatment for FXS in order to achieve a standardized diagnosis, treatment and prevention for patients and families affected by this disease.
Child ; Humans ; Autism Spectrum Disorder/therapy* ; Fragile X Mental Retardation Protein/genetics* ; Fragile X Syndrome/therapy* ; Intellectual Disability/genetics*