Species-conserved SYNGAP1 phenotypes associated with neurodevelopmental disorders

Mol Cell Neurosci. 2018 Sep;91:140-150. doi: 10.1016/j.mcn.2018.03.008. Epub 2018 Mar 24.

Abstract

SYNGAP1 loss-of-function variants are causally associated with intellectual disability, severe epilepsy, autism spectrum disorder and schizophrenia. While there are hundreds of genetic risk factors for neurodevelopmental disorders (NDDs), this gene is somewhat unique because of the frequency and penetrance of loss-of-function variants found in patients combined with the range of brain disorders associated with SYNGAP1 pathogenicity. These clinical findings indicate that SYNGAP1 regulates fundamental neurodevelopmental processes that are necessary for brain development. Here, we describe four phenotypic domains that are controlled by Syngap1 expression across vertebrate species. Two domains, the maturation of cognitive functions and maintenance of excitatory-inhibitory balance, are defined exclusively through a review of the current literature. Two additional domains are defined by integrating the current literature with new data indicating that SYNGAP1/Syngap1 regulates innate survival behaviors and brain structure. These four phenotypic domains are commonly disrupted in NDDs, suggesting that a deeper understanding of developmental Syngap1 functions will be generalizable to other NDDs of known or unknown etiology. Therefore, we discuss the known molecular and cellular functions of Syngap1 and consider how these functions may contribute to the emergence of disease-relevant phenotypes. Finally, we identify major unexplored areas of Syngap1 neurobiology and discuss how a deeper understanding of this gene may uncover general principles of NDD pathobiology.

Keywords: Autism spectrum disorder; Circuits; Cognitive impairment; Epilepsy; Intellectual disability; Microcephaly; Neurodevelopment; SynGAP; Synapse; Syngap1.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Conserved Sequence
  • Humans
  • Loss of Function Mutation
  • Mice
  • Neurodevelopmental Disorders / genetics*
  • Neurodevelopmental Disorders / metabolism
  • Neurodevelopmental Disorders / pathology
  • Phenotype*
  • ras GTPase-Activating Proteins / chemistry
  • ras GTPase-Activating Proteins / genetics*
  • ras GTPase-Activating Proteins / metabolism

Substances

  • Syngap1 protein, mouse
  • ras GTPase-Activating Proteins