FMNL2 and Intellectual disability: This gene covaries with a number of Chr 2 positional candidates, including Arl5, Mbd5, and Fmnl2. Mbd5 has recently been identified as the causal locus of the 2q23.1 microdeletion syndrome in humans, the symptoms of which are intellectual disability, epilepsy, and autism spectrum disorders [91]–[93].