Targeted treatments in fragile X syndrome

Abstract

Introduction: Mouse models of fragile X syndrome (FXS), the most common cause of inherited intellectual disability, show decreased GABAergic input and overactive metabotropic glutamate receptor (mGluR) system, which result in an imbalance between excitatory (Glutamate) and inhibitory (GABA) systems in the brain. The cognitive, behavioral and neurological impairments require the development of targeted treatments that focus on regulating the mGluR and GABA pathways. The increasing literature on this topic and controversial results suggest the need for a comprehensive review of the literature and our expert opinion.

Areas covered: This article includes an extended review of the literature and comprehensive analysis of the current studies in humans and animal models with FXS.

Expert opinion: Our expert opinion is that these orphan drugs will help reduce, but not completely ameliorate, the behavioral phenotype of FXS through improved synaptic plasticity. Single-compound treatment may not be enough for the most affected individuals with FXS and although the orphan drugs may improve more generalized symptoms of FXS compared to symptom-based treatments, the most effective treatment response will require a multifaceted approach starting early in life using multiple pharmacological and behavioral interventions. More research is needed to assess how combinations of these medications, along with behavioral intervention and educational opportunities, will best reverse phenotypic features of FXS. The clinical trials of FXS are challenging, but offers hope for effective treatments for this syndrome and other related neurodevelopmental disorders, including autism.

Keywords::

• AFQ056
• arbaclofen
• fragile X mental retardation 1
• fragile X syndrome
• ganaxolone
• lovastatin
• mavoglurant
• minocycline
• RO4917523
• targeted treatments

Notes

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