Identification of microsatellite markers &lt;1 Mb from the FMR1 CGG repeat and development of a single-tube tetradecaplex PCR panel of highly polymorphic markers for preimplantation genetic diagnosis of fragile X syndrome

Chen, Min; Zhao, Mingjue; Lee, Caroline; Chong, Samuel S.

doi:10.1038/gim.2015.185

Cited by 8 publications

(13 citation statements)

References 36 publications

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“…For example, methylation-specific quantitative melt analysis (MS-QMA), respectively, identified methylation mosaicism in an additional 15% and 11% of patients in the Chilean and Australian reports, suggesting the presence of a cryptic FM [ 5 , 6 ]. Other methods include a variety of polymerase chain reaction (PCR) techniques, such as high polymorphism markers for preimplantation genetic diagnosis (PGD) of FXS [ 7 ] and two PCR analyses (PCR screening and PCR premutation) [ 8 ]. However, it is difficult to draw a solid criterion due to different inclusive criteria, diagnostic methods, and sample sizes within each study.…”

Section: Introductionmentioning

confidence: 99%

Impaired GABA Neural Circuits Are Critical for Fragile X Syndrome

Gao

Yang

et al. 2018

Neural Plasticity

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Fragile X syndrome (FXS) is an inheritable neuropsychological disease caused by silence of the fmr1 gene and the deficiency of Fragile X mental retardation protein (FMRP). Patients present neuronal alterations that lead to severe intellectual disability and altered sleep rhythms. However, the neural circuit mechanisms underlying FXS remain unclear. Previous studies have suggested that metabolic glutamate and gamma-aminobutyric acid (GABA) receptors/circuits are two counter-balanced factors involved in FXS pathophysiology. More and more studies demonstrated that attenuated GABAergic circuits in the absence of FMRP are critical for abnormal progression of FXS. Here, we reviewed the changes of GABA neural circuits that were attributed to intellectual-deficient FXS, from several aspects including deregulated GABA metabolism, decreased expressions of GABA receptor subunits, and impaired GABAergic neural circuits. Furthermore, the activities of GABA neural circuits are modulated by circadian rhythm of FMRP metabolism and reviewed the abnormal condition of FXS mice or patients.

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Section: Introductionmentioning

confidence: 99%

Impaired GABA Neural Circuits Are Critical for Fragile X Syndrome

Gao

Yang

et al. 2018

Neural Plasticity

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“…Currently, PCR has been wildly used to detect various human diseases, such as Alzheimer's disease and human kidney diseases (26,27). Previous study has indicated that a single-tube tetradecaplex PCR panel of highly polymorphic markers can act as a genetic diagnosis of FXS (15). In this study, we indicated that nested PCR is an efficient method in diagnosis of FXS patients, which is more efficient than single-tube tetradecaplex PCR panel.…”

Section: Discussionmentioning

confidence: 68%

“…Study has found that single-tube polymerase chain reaction (PCR) panel of highly polymorphic markers is an efficient method for preimplantation genetic diagnosis of FXS (15). Interestingly, nested PCR presents higher specificity than traditional PCR using two sets of primers (16).…”

Section: Introductionmentioning

confidence: 99%

Assessment of efficacy of prenatal genetic diagnosis for fragile X syndrome using nested PCR

Miao¹,

Liu²,

Li³

et al. 2018

Exp Ther Med

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Abstract. Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability and the leading monogenic cause of autism spectrum disorder. It has previously been demonstrated that prenatal genetic diagnosis is efficient for the diagnosis of FXS. The present study investigated the diagnostic effects of nested polymerase chain reaction (PCR) for fragile X mental retardation 1 (FMR1) and expanded CGG repeats. It was demonstrated that the nested PCR assay rapidly measured the multi-copies of the FMR1 gene in individual samples. The nested PCR assay detected normal CGG repeat lengths and expanded CGG repeat lengths with a low occurrence of false positives. In addition, the nested PCR assay resulted in increased sensitivity and specificity for patients with FXS. Furthermore, the nested PCR assay identified the mutation and generated conclusive cases for FXS, indicating that this assay is beneficial for the diagnosis of FXS patients. In conclusion, these outcomes indicate that nested PCR assay is a reliable and easier method for diagnosis of FXS, which may be used for the diagnosis of FXS patients. IntroductionFragile X syndrome (FXS) is one of the most common monogenic diseases that can lead to autism spectrum disorder and intellectual disability (1). Genetic diagnosis shows that FXS is an X-linked genetic disorder that is characterized by behavioral problems and specific physical dysmorphisms (2). Child patients with FXS have ritualistic behaviors and social deficits and study has provided for early recognition and diagnosis for the children patients (3). Previous study indicated that FXS included the clinical manifestations, such as language delay, intellectual dysfunction, behavioral and social problems, and other physical malformations (4). In recent years, although various medical treatments have been applied for patients with FXS, a spectrum of medical problems are commonly experienced by people with FXS, such as otitis media, seizures, and gastrointestinal problems (5). Therefore, the efficacy of prenatal genetic diagnosis for FXS plays essential role for prenatal diseases testing.Currently, FXS is regarded as a monogenic disease caused by expansion of a trinucleotide repeat in the 5' untranslated region of the fragile X mental retardation 1 (FMR1) gene (6). The FMR1 gene is a microsatellite locus that contains <55 CGG repeats in its 5'-untranslated region on Xq27.3 (7). Bioinformatics has indicated that CGG repeat (>200 CGG repeats) in its 5'-untranslated region is associated with fragile X tremor and ataxia syndrome (FXTAS) by silencing FMR1 gene and resulting in FXS (8,9). The abnormal CGG expansion results in methylation and transcriptional silencing of the FMR1 gene, which subsequently leads to a reduction or loss of fragile X mental retardation 1 protein (FMRP) (10). Additionally, previous study has indicated that methylation of the FMR1 gene exon 1/intron 1 boundary positioned fragile X related epigenetic element 2 (FREE2) affects X-chromosome inactivation (XCI) in FXS full mutation (1...

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“…We have developed a fragile X syndrome PGD strategy that couples direct detection of the FMR1 CGG repeat expansion by TP-PCR, with linked multi-marker haplotype analysis and gender determination using a tetradecaplex STR PCR assay that we recently described (Ref. 23 ). We have successfully applied this combined FMR1 TP-PCR and tetradecaplex marker PCR assay to a simulated PGD case and two cycles of a clinical IVF-PGD case.…”

Section: Introductionmentioning

confidence: 99%

FMR1 CGG repeat expansion mutation detection and linked haplotype analysis for reliable and accurate preimplantation genetic diagnosis of fragile X syndrome

Rajan‐Babu

Lian

Cheah

et al. 2017

Expert Rev. Mol. Med.

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Fragile X mental retardation 1 (FMR1) full-mutation expansion causes fragile X syndrome. Trans-generational fragile X syndrome transmission can be avoided by preimplantation genetic diagnosis (PGD). We describe a robust PGD strategy that can be applied to virtually any couple at risk of transmitting fragile X syndrome. This novel strategy utilises whole-genome amplification, followed by triplet-primed polymerase chain reaction (TP-PCR) for robust detection of expanded FMR1 alleles, in parallel with linked multi-marker haplotype analysis of 13 highly polymorphic microsatellite markers located within 1 Mb of the FMR1 CGG repeat, and the AMELX/Y dimorphism for gender identification. The assay was optimised and validated on single lymphoblasts isolated from fragile X reference cell lines, and applied to a simulated PGD case and a clinical in vitro fertilisation (IVF)-PGD case. In the simulated PGD case, definitive diagnosis of the expected results was achieved for all ‘embryos’. In the clinical IVF-PGD case, delivery of a healthy baby girl was achieved after transfer of an expansion-negative blastocyst. FMR1 TP-PCR reliably detects presence of expansion mutations and obviates reliance on informative normal alleles for determining expansion status in female embryos. Together with multi-marker haplotyping and gender determination, misdiagnosis and diagnostic ambiguity due to allele dropout is minimised, and couple-specific assay customisation can be avoided.

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Identification of microsatellite markers <1 Mb from the FMR1 CGG repeat and development of a single-tube tetradecaplex PCR panel of highly polymorphic markers for preimplantation genetic diagnosis of fragile X syndrome

Cited by 8 publications

References 36 publications

Impaired GABA Neural Circuits Are Critical for Fragile X Syndrome

Impaired GABA Neural Circuits Are Critical for Fragile X Syndrome

Assessment of efficacy of prenatal genetic diagnosis for fragile X syndrome using nested PCR

FMR1 CGG repeat expansion mutation detection and linked haplotype analysis for reliable and accurate preimplantation genetic diagnosis of fragile X syndrome

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