Progressive multifocal leukoencephalopathy in a young adult with DOCK8 deficiency: a case of JC virus reactivation in primary immunodeficiency.

Progressive multifocal leukoencephalopathy (PML) is a rare, often fatal demyelinating disease of the central nervous system (CNS) caused by JC virus (JCV) reactivation in the setting of impaired cellular immunity. While commonly associated with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) and immunosuppressive therapies, PML can also arise in primary immunodeficiency disorders. We report a case of PML in a young adult with autosomal recessive hyper-IgE syndrome (AR-HIES) due to DOCK8 deficiency, highlighting the importance of considering genetic immunodeficiencies in cases of JCV-PML without known iatrogenic or acquired causes.