Creutzfeldt-Jacob disease associated with the PRNP codon 200Lys mutation: an analysis of 45 families.

200Lys mutation in the human PRNP coding region has been identified in 45 of the 55 CJD-affected families thus far presented to our NIH laboratory. These codon 200Lys families have a total of 87 patients, and originate from 7 different countries: Slovakia, Poland, Germany, Tunisia, Greece, Libya, and Chile. Forty-seven patients were neuropathologically verified, and brain tissue from 14 patients transmitted disease to experimental primates. The mutation was found by direct sequencing in 4 patients, and it was detected by restriction endonuclease analysis with BsmA 1 and/or the single nucleotide extension reaction in 36 other patients and 45 of 109 first degree relatives (1 parent, 14 siblings, and 30 children). The mutation is associated with all known geographical clusters of CJD (Slovakia, Libyan Jews, Chile) in which the annual mortality rate is tens or hundreds of times higher than the world average of 1 per million. All patients originating from the cluster areas carried the mutation, but it was seen in only 1 of 103 unrelated control individuals from the same areas, and in none of 102 controls from other areas, indicating a strong association between the mutation and disease. The penetrance of the mutation was estimated to be 0.56. Branches of some families migrating from cluster areas to other countries continue to have CJD over several generations, suggesting that CJD in these families is a genetic disorder, in which the 200Lys mutation is responsible for the disease.