extracellular domain of gamma-aminobutyric acid receptor subunit rho-1 (GABA-rho1 or GABRR1)
This family contains extracellular domain (ECD) of the rho subunit 1 of type-A gamma-aminobutyric acid receptor (GABAAR), encoded by the GABRR1 gene, expressed in many areas of the brain, but especially high in the retina. GABRR1 exists next to GABRR2 (encoding rho subunit 2) on the chromosome region thought to be associated with susceptibility for psychiatric disorders and epilepsy. Close proximity of the rho1 and rho2 subunit genes suggests that they emerged via a local duplication event. This subunit homo-oligomerizes to form GABAA-rho receptors (formerly classified as GABA-rho or GABAc receptor), but does not co-assemble with any of the classical GABAAR subunits. In humans, mutations in the GABRR1 gene may be responsible for some cases of autosomal recessive retinitis pigmentosa. Variation in GABRR1 is also associated with susceptibility to bipolar schizoaffective disorder, and may be associated with alcohol dependency.