A prion protein variant in a family with the telencephalic form of Gerstmann‐Sträussler‐Scheinker syndrome

We present a patient with a mutation in the open reading frame of the prion protein gene (PRNP), which results in substitution of valine for alanine at codon 117. The patient is a member of a large American kindred of German descent with the telencephalic form of Gerstmann‐Straussler‐Scheinker syndrome (GSS). Two other affected members of this kindred carried this mutation, as inferred from haplotypes of their offspring and spouses. The mutation was absent in one member with a protracted neurologic illness that differed from the other affected members9 illnesses. The identification of a distinct PRNP mutation in the telencephalic form of GSS supports the hypothesis that allelic forms of PRNP may correspond to distinct clinical disease entities. NEUROLOGY 1991;41:681‐684