<prompt> Gamma amino butyrate is synthesized fromFumarateGlutamateHistidineGlycine  <response>: Gamma-aminobutyric acid or GABA is formed by decarboxylation of glutamate in presence of enzyme glutamate decarboxylase.Ref: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 224, Fig 17.2 