GABRA1 is a human gene whose product the GABA-A Receptor Pi Subunit (GABRP) encodes the pi (pi) subunit of the GABA-A receptor, a ligand-gated chloride channel that mediates inhibitory neurotransmission in the central nervous system [1](https://doi.org/10.1016/j.neuroscience.2015.06.015). The pi subunit is uniquely expressed in reproductive tissues and brain, where it assembles with other subunits to form receptor isoforms with distinct pharmacological and physiological properties. Variants in GABRA1 have been implicated in Epilepsy, [Alzheimer's Disease](/diseases/alzheimers-disease), Cancer. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration. [@tanaka2018]
GABRA1 is a human gene whose product the GABA-A Receptor Pi Subunit (GABRP) encodes the pi (pi) subunit of the GABA-A receptor, a ligand-gated chloride channel that mediates inhibitory neurotransmission in the central nervous system [1](https://doi.org/10.1016/j.neuroscience.2015.06.015). The pi subunit is uniquely expressed in reproductive tissues and brain, where it assembles with other subunits to form receptor isoforms with distinct pharmacological and physiological properties. Variants in GABRA1 have been implicated in Epilepsy, [Alzheimer's Disease](/diseases/alzheimers-disease), Cancer. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration. [@tanaka2018]
The GABA-A Receptor Pi Subunit (GABRP) encodes the π (pi) subunit of the GABA-A receptor, a ligand-gated chloride channel that mediates inhibitory neurotransmission in the central nervous system [1](https://doi.org/10.1016/j.neuroscience.2015.06.015). The pi subunit is uniquely expressed in reproductive tissues and brain, where it assembles with other subunits to form receptor isoforms with distinct pharmacological and physiological properties.
GABRP-containing receptors exhibit reduced benzodiazepine sensitivity and altered gating kinetics compared to receptors lacking the pi subunit [2](https://doi.org/10.1016/j.brainres.2016.08.020). The pi subunit contains a unique cytoplasmic loop that interacts with scaffolding proteins and influences receptor trafficking to the plasma membrane.
Disease Associations
Epilepsy
GABRP variants have been associated with epilepsy susceptibility, particularly in temporal lobe epilepsy [3](https://doi.org/10.1016/j.yebeh.2018.01.018). Altered GABA-A receptor function due to pi subunit dysregulation may contribute to hyperexcitability and seizure generation.
Alzheimer's Disease
GABRP expression is altered in Alzheimer's disease brain, particularly in regions vulnerable to neurodegeneration [4](https://doi.org/10.1016/j.neurobiolaging.2017.02.012). The pi subunit may modulate [Aβ](/proteins/amyloid-beta)-induced toxicity through effects on inhibitory neurotransmission.
Cancer
GABRP is highly expressed in estrogen receptor-positive breast cancer and has been investigated as a potential therapeutic target [5](https://doi.org/10.1038/onc.2016.403).