ARHGEF9 and syndromic intellectual disability: The Gabra2-1 model has relevance for the growing number of patients with encephalopathic epilepsy caused by mutation in GABRA2 [11, 76, 77], as well as ARHGEF9 intellectual disability syndrome [10, 78], which impairs collybistin and causes a loss of α2 subunit containing GABAA receptors at subtypes of inhibitory synapses [10].