Genetics of Progressive Multifocal Leukoencephalopathy and Acquired Immunodeficiency Syndrome

This study will identify genetic factors associated with the development of progressive multifocal leukoencephalopathy (PML) in patients with acquired immunodeficiency syndrome (AIDS). PML is a life-threatening infection of the brain that affects about 5 percent of untreated patients with AIDS. Its symptoms include mental deterioration, vision loss, speech disturbances, ataxia (inability to coordinate movements), paralysis, and coma. PML is caused by a polyomavirus called the JC virus. It is estimated that up to 80 percent of the human population has been exposed to the JC virus, but the disease is very rare. The virus only becomes active in people who have compromised immune systems, such as those undergoing immune suppressive chemotherapy for cancer and those with damaged immune systems due to HIV. Patients who have participated in the Multicenter AIDS Cohort Study may be eligible for this study, as well as healthy normal volunteers who will serve as controls. The study will review clinical information from patients and analyze genetic factors from both patients and control subjects to investigate genes associated with AIDS and JC virus infection.