Progressive multifocal leukoencephalopathy
Type of disease: Infectious disease | Cancer | Rare conditions
Progressive multifocal leukoencephalopathy (PML) is a neurological disorder that damages the myelin that covers and protects nerves in the white matter of the brain. It is caused by the JC virus (JCV). By age 10, most people have been infected with this virus, but it rarely causes symptoms unless the immune system becomes severely weakened. The disease occurs, rarely, in organ transplant patients; people undergoing chronic corticosteroid or immunosuppressive therapy; and individuals with cancer, such as HodgkinÕs disease, lymphoma, and sarcoidosis. PML is most common among individuals with acquired immune deficiency syndrome (AIDS). Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.