Multifarious Functions of the Fragile X Mental Retardation Protein

Trends Genet. 2017 Oct;33(10):703-714. doi: 10.1016/j.tig.2017.07.008. Epub 2017 Aug 18.


Fragile X syndrome (FXS), a heritable intellectual and autism spectrum disorder (ASD), results from the loss of Fragile X mental retardation protein (FMRP). This neurodevelopmental disease state exhibits neural circuit hyperconnectivity and hyperexcitability. Canonically, FMRP functions as an mRNA-binding translation suppressor, but recent findings have enormously expanded its proposed roles. Although connections between burgeoning FMRP functions remain unknown, recent advances have extended understanding of its involvement in RNA, channel, and protein binding that modulate calcium signaling, activity-dependent critical period development, and the excitation-inhibition (E/I) neural circuitry balance. In this review, we contextualize 3 years of FXS model research. Future directions extrapolated from recent advances focus on discovering links between FMRP roles to determine whether FMRP has a multitude of unrelated functions or whether combinatorial mechanisms can explain its multifaceted existence.

Keywords: Fragile X syndrome (FXS); activity-dependent critical period; autism spectrum disorder (ASD); synapse; translation regulation.

Publication types

  • Review
  • Research Support, N.I.H., Extramural

MeSH terms

  • Fragile X Mental Retardation Protein / genetics
  • Fragile X Mental Retardation Protein / physiology*
  • Fragile X Syndrome / genetics
  • Humans


  • FMR1 protein, human
  • Fragile X Mental Retardation Protein