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Molecular Biomarkers in Fragile X Syndrome

Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, Sacramento, CA 95817, USA
MIND Institute, University of California Davis Medical Center, Sacramento, CA 95817, USA
Author to whom correspondence should be addressed.
Brain Sci. 2019, 9(5), 96;
Received: 7 March 2019 / Revised: 22 April 2019 / Accepted: 24 April 2019 / Published: 27 April 2019
(This article belongs to the Special Issue Towards Mechanism-based Treatments for Fragile X Syndrome)
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Fragile X syndrome (FXS) is the most common inherited form of intellectual disability (ID) and a known monogenic cause of autism spectrum disorder (ASD). It is a trinucleotide repeat disorder, in which more than 200 CGG repeats in the 5’ untranslated region (UTR) of the fragile X mental retardation 1 (FMR1) gene causes methylation of the promoter with consequent silencing of the gene, ultimately leading to the loss of the encoded fragile X mental retardation 1 protein, FMRP. FMRP is an RNA binding protein that plays a primary role as a repressor of translation of various mRNAs, many of which are involved in the maintenance and development of neuronal synaptic function and plasticity. In addition to intellectual disability, patients with FXS face several behavioral challenges, including anxiety, hyperactivity, seizures, repetitive behavior, and problems with executive and language performance. Currently, there is no cure or approved medication for the treatment of the underlying causes of FXS, but in the past few years, our knowledge about the proteins and pathways that are dysregulated by the loss of FMRP has increased, leading to clinical trials and to the path of developing molecular biomarkers for identifying potential targets for therapies. In this paper, we review candidate molecular biomarkers that have been identified in preclinical studies in the FXS mouse animal model and are now under validation for human applications or have already made their way to clinical trials. View Full-Text
Keywords: fragile X syndrome; molecular biomarkers; FMR1; FMRP; intellectual disability; Fmr1 KO mouse; ASD fragile X syndrome; molecular biomarkers; FMR1; FMRP; intellectual disability; Fmr1 KO mouse; ASD

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This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

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Zafarullah, M.; Tassone, F. Molecular Biomarkers in Fragile X Syndrome. Brain Sci. 2019, 9, 96.

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