Interestingly, regions within both Gpc4 and RPTPδ have been identified as potential HARs (Doan et al., 2016), and two cases of ASD with intellectual disability (ID) were found that have point mutations in HARs of Gpc4 causing a significant decrease in Gpc4 expression (Doan et al., 2016). The gene discussed is HARS1; the disease is Intellectual disability.