of the GABAA receptor gene GABRG2 gene (located on chromosome 5) in both A/II-1 and A/II-4. Sanger sequencing indicated that the p.Glu402fs*3 variant was segregated within all affected family members of the first branch, but was not present in individual A/II-9 (figure 1). The variant created a frameshift at codon Glu402 leading to a new reading frame that ended in a stop codon 2 positions downstream (p.Glu402fs*3). Several arguments pointed toward the pathogenicity of the GABRG2 variant in the family: (1) the GABRG2 gene is known to be implicated in familial epilepsies; (2) this variant disrupts the reading frame leading to a loss-of-function mechanism, as previously reported for other mutations16; and (3) this truncating variant segregated among affected family members (apart from A/II-9). We therefore considered individual A/II-9 as a phenocopy. We reviewed the history of seizures of individual A/II-9, which consisted of few episodes of FS between ages 1 and 4 years. During adolescence, she presented a unique probable focal seizure with loss of consciousness and gestural automatisms and 2 GTCS (1 nocturnal and 1 diurnal), over a period of 6 months (period of emotional stress). We also noted that the mother of individual A/II-9 was asymptomatic, as well
