New variant prion protein in a Japanese family with Gerstmann-Sträussler syndrome.

We found novel variants in the open reading frame of the prion protein (PrP) gene in a family with Gerstmann-Sträussler syndrome (GSS). Codon 219Lys variant is a normal polymorphism which we found recently. Some GSS cases were identified with codon 102 mutation (proline to leucine) and codon 219Lys polymorphism. While two families had a codon 102 mutation and codon 219Lys polymorphism in different alleles, 4 patients in one family had both in the same allele. The clinicopathological features of these 4 patients were clearly different from previously reported GSS patients with codon 102 mutation. These cases should be reported as a new variant of GSS.