Gertsmann-Straussler-Scheinker syndrome. Light micrograph of the brain of a patient suffering from Gertsmann- Straussler-Scheinker syndrome. This is an inherited prion disease which is related to Creutzfeldt-Jakob disease (CJD), the human form of mad cow disease. The brain tissue is studded with brown plaques and white gaps. The brain of such a patient will appear spongy with severe loss of tissue. Such changes will result in unsteady gait, loss of coordination, and progress- ive dementia. Patients with this syndrome have a genetic mutation in a gene which results in the production of a virus-like protein particle called a prion. Prions are linked to CJD & mad cow disease.