Our cohort includes 116 patients from three sources: previously reported individuals (58.6%), individual referrals to the SLC6A1 Connect Foundation (15.5%), and the Epi25 Collaborative for Large-Scale Whole Genome Sequencing in Epilepsy Collaborative Database (25.8%) (Epi25 Collaborative, 2019). Here, SLC6A1 is linked to epilepsy.