Specht et al., "Polymorphisms in the GAD2
gene-region are associated with susceptibility for unipolar depression and with a risk factor for anxiety disorders," American Journal of Medical Genetics Part B: Neuropsychiatric Genetics, vol.
In mammals, GAD exists in two isoforms encoded by two different genes--GAD1 and GAD2
. GAD1 and GAD2
are expressed in the brain where GABA is used as a neurotransmitter; GAD2
is also expressed in the pancreas.
GAD1 is expressed in root tissues only, while GAD2
is expressed in roots, leaves, inflorescence stems, and flowers (Zik et al., 1998).