GAD2 and Cognitive impairment: Defects in the human Gad1 homolog proteins GAD67 and GAD65 were found in patients suffering from different neurodegenerative diseases including Parkinson, Huntington and Alzheimer’s41–43 or cognitive disorders like idiopathic autisms or schizophrenia44–46, suggesting that a tight regulation of this enzyme is critical to preserve normal brain functioning.