extracellular domain of gamma-aminobutyric acid receptor subunit rho
This family contains extracellular domain of rho subunits (rho1, rho2, and rho3, encoded by GABRR1, GABRR2, and GABRR3, respectively) of type-A gamma-aminobutyric acid receptor (GABAAR). These subunits homo-oligomerize to form GABAA-rho receptors (formerly classified as GABA-rho or GABAC receptor), but do not co-assemble with any of the classical GABAA subunits. They are especially high expression in the retina and their distinctive pharmacological properties are unique; they are not modulated by many GABAA receptor modulators such as barbiturates, benzodiazepines, and neuroactive steroids. In humans, mutations in the GABRR1 and GABRR2 genes may be responsible for some cases of autosomal recessive retinitis pigmentosa. Variation in GABRR1 is also associated with susceptibility to bipolar schizoaffective disorder while a SNP in GABRR2 has been reported to show association with autism.