SLC6A1 and epilepsy, early-onset: Furthermore, likely pathogenic variants in SLC6A1 were identified in 6/160 (4%) individuals with a previously undiagnosed early-onset epilepsy with myoclonic atonic seizures (Carvill et al., 2015) and additional studies identified individual patients with autism spectrum disorder and developmental epileptic encephalopathy carrying variants in SLC6A1 (Rauch et al., 2012; Sanders et al., 2012).