GAD2 and epilepsy: Subsequent electroencephalographic (EEG) and electromyographic (EMG) characterization showed the presence of spontaneous generalized tonic-clonic (GTC) seizures (Figure 7A), interictal spikes and myoclonic seizures in Gad2:Ndufs4cKO mice (Figure 7B–C), which are hallmarks of epilepsy in mitochondrial disorders (Rahman, 2015), with 40–60% of mitochondrial disease patients manifesting seizures (Koenig, 2008; El Sabbagh et al., 2010; Canafoglia et al., 2001).