RAI1 and cerebellar ataxia: RAI1 is thought to be key to normal brain development and function due to its association with a number of neurobehavioral disorders which, besides SMS, include Potocki–Lupski syndrome (Potocki et al., 2007), schizophrenia (Joober et al., 1999), autism (van der Zwaag et al., 2009), Parkinson disease (Do et al., 2011), and cerebellar ataxia (Hayes et al., 2000).