Gerstmann-Sträussler-Scheinker syndrome (GSS) is a human transmissible spongiform encephalopathy recently linked to the human analog of the prion protein gene (PRNP) on chromosome 20p. We have studied a large German GSS family for linkage to PRNP and have obtained a peak lod score of 1.15 at a recombination fraction (theta) of 0.00. This result provides additional evidence that GSS is linked to a mutation in codon 102 of the PRNP gene. Combining our data with linkage data previously reported yields a peak lod score of 4.52 at theta = 0.0. No evidence for linkage heterogeneity was found in the combined data set.