More and more is written on Beta 3 receptors in human bladders and their role in detrusor relaxation. This study from Japan investigated human Beta 3 AR gene which is polymorphic. One hundred women with overactive bladder (OAB) and 101 healthy women without OAB were studied. Hair root samples were obtained from all subjects and Beta 3 AR gene was analysed. The incidence of gene variation was 47% in OAB as compared to 22.8% in the non-OAB control group. Although a small study, it does indicate that polymorphism in Beta 3 AR gene may be associated with OAB syndrome.