GAD2 and meningoencephalitis: In addition, anti-glutamic acid decarboxylase-65 (GAD65), an enzyme that converts excitatory glutamate to inhibitory gamma-aminobutyric acid (GABA), can lead to a range of disorders, such as tonic syndrome, cerebellar ataxia, epilepsy, limbic encephalitis, and meningoencephalitis (Muñoz-Lopetegi et al., 2020; Kuang et al., 2023).