at least 1 of 2 in silico prediction tools (Sift, http://sift.jcvi.org/; PolyPhen-2, http://genetics.bwh.harvard.edu/pph2/). We followed the guidelines for assigning causality of sequence variants in human disease as outlined.14 Coverage of GABRG2 was satisfactory (>250×) except for exon 6, which was subsequently analyzed by traditional Sanger sequencing. Filtered variants were validated by Sanger sequencing, and segregation was analyzed in all available family members. Impact of mutations was assessed with Alamut version 2.4.3 (Interactive Biosoftware). GABRG2 mutations were mapped on the immature peptide, according to the current convention.15,16 We compared the frequency of rare nonsynonymous GABRG2 variants (including missense, nonsense, essential splice-site, in-frame Indels) identified in patients with epilepsy and those present in 33,370 European cases from the publicly available Exome Aggregation Consortium (ExAC) database (http://exac.broadinstitute.org) using Fisher exact tests (accessed July 2015).
