Family E comprised a father and 2 daughters with FS, followed by early-onset absence seizures and GTCS. Development was normal in all 3 family members. Despite a high seizure frequency, especially in the father, all became seizure-free with valproate. A missense variant, c.595A>G/p.Met199Val in exon 5 of GABRG2, was found in the 3 patients. The variant was predicted deleterious by Sift, disease-causing by MutationTaster, and probably damaging by PolyPhen-2. The p.Met199Val mutation is located in the N-terminal extracellular loop of the protein (figure 2).
