General description

JC Virus Granule Cell Neuronopathy (JCV GCN) is a neurological disease distinct from Progressive multifocal leukoencephalopathy (PML). It is caused by a mutation of VP1 gene of the JC virus, which alters its tropism from glial cells to cerebellar granule cells. Unlike PML, JCV GCN specifically affects granule cell neurons in the cerebellum without involving oligodendrocytes.

The disease occurs due to the reactivation of the JC virus in immunocompromised individuals. Major risk factors include HIV/AIDS, immunosuppressive monoclonal antibody therapy (such as rituximab and natalizumab), lymphoma, and sarcoidosis. Clinically, patients present with progressive subacute or chronic cerebellar and brainstem dysfunction, leading to symptoms such as gait disturbance, dysarthria, ataxia, and nystagmus.

References

1. Dang, Louis, et al. "JC polyomavirus granule cell neuronopathy in a patient treated with rituximab." JAMA neurology 71.4 (2014): 487-489.