RHOA and Intellectual disability: These include homozygous loss‐of‐function variants in the ARHGEF2 gene (OMIM 607560), associated with mental retardations in humans, resulting in the inhibition of the RhoA‐ROCK‐MLC pathway activation, which in turn is critical for cell motility; altered migration of pre‐cerebellar immature neurons has been observed in the ARHGEF2−/− mice.26