FMR1

Receptor

Neuroscience

Biology

Gene

Fragile X syndrome

Channelopathy

Intellectual disability

Ion channel

Loss function

Phenotype

Fragile x

Genetics

Medicine

Nature reviews. Neuroscience

Fragile X syndrome (FXS) is the most common inherited form of intellectual disability and the leading monogenic cause of autism. The condition stems from loss of fragile X mental retardation protein (FMRP), which regulates a wide range of ion channels via translational control, protein–protein interactions and second messenger pathways. Rapidly increasing evidence demonstrates that loss of FMRP leads to numerous ion channel dysfunctions (that is, channelopathies), which in turn contribute significantly to FXS pathophysiology. Consistent with this, pharmacological or genetic interventions that target dysregulated ion channels effectively restore neuronal excitability, synaptic function and behavioural phenotypes in FXS animal models. Recent studies further support a role for direct and rapid FMRP–channel interactions in regulating ion channel function. This Review lays out the current state of knowledge in the field regarding channelopathies and the pathogenesis of FXS, including promising therapeutic implications. Ion channel dysfunctions contribute significantly to fragile X pathophysiology. In this Review, Deng and Klyachko discuss the mechanisms underlying the effects of these channelopathies in fragile X syndrome, and the therapeutic potential of pharmacological interventions that target ion channels.

Channelopathies in fragile X syndrome