The importance of aGPCRs in human health is further underscored in diseases in which they are disrupted, such as bilateral frontoparietal polymicrogyria (GPR56) [58,59], Usher Syndrome (GPR98) [60-62], glioblastomas (BAI1) [63,64], susceptibility to brain arteriovenous malformation (GPR124) [65], and breast cancer metastasis (GPR116) [66]. Here, ADGRA2 is linked to Usher syndrome.