CCR2 and AIDS dementia complex: Only a single study found associations between CCR-2 gene polymorphisms and HIV-associated neuropsychological impairment, where the CCR2-64I allele was associated with a greater rate of progression to NCI over time in adults [87]; several other studies found no effects with NCI or AIDS dementia in HIV+ adults [91,92], or impairment in various cognitive domains in children [85] with HIV.