This is in agreement with a previous study which found no effect of DAT genotype on disease severity and brain function in HIV-infected patients (Levine et al. 2012) while another group identified that the DRD3 genetic polymorphism relates with cognitive impairment in methamphetamine/HIV-infected people (Gupta et al. 2011). The gene discussed is SLC6A3; the disease is Cognitive impairment.