GERSTMANN-STRAUSSLER-SCHEINKER DISEASE (PRNP P102L) - AMYLOID DEPOSITS ARE BEST RECOGNIZED BY ANTIBODIES DIRECTED TO EPITOPES IN PRP REGION 90-165

Gerstmann-Straussler-Scheinker (GSS) disease is a familial neurological disorder pathologically characterized by accumulation of prion protein (PrP) in the form of fibrillary and non-fibrillary deposits within the cerebrum and cerebellum. We have studied two patients in whom the disease is caused by a leucine for proline amino acid substitution at residue 102 of PrP. In both patients, me neuropathologic findings are similar, consisting of spongiform changes, amyloid deposits, and gliosis. To investigate the antigenic profile of PrP deposits, we used antibodies raised against several peptides that correspond to segments of the N-terminus, repeat region, midregion, and C-terminus of PrP. By immunohistochemistry, PrP amyloid cores are best labeled by antibodies directed to epitopes spanning PrP residues 90-165. In GSS disease caused by a substitution of thymine to cytosine at PRNP codon 198 (Indiana kindred), the major amyloidogenic peptide spans residues 58-150; therefore, in these two genetic forms of GSS disease, amyloid may be composed of different peptides.