The purpose of this study is to identify host genetic factors that contribute to the development of Progressive Multifocal Leukoencephalopathy (PML) associated with JC virus. JC virus is one of many opportunistic infections that arise in AIDS patients. JC virus is widely distributed in the general population, with estimates of population exposure ranging from 30-80%. JC virus remains latent in the host, and in profoundly immunosuppressed patients, JC virus can cause PML, a fatal disease associated with neurotropic JC virus that lytically infects oligodendrocytes. In untreated AIDS populations, the frequency of PML has been estimated at roughly 5%. This study will identify host genetic factors that may contribute to the development of PML in the AIDS population.
