J. Chapman et al., THE RISK OF DEVELOPING CREUTZFELDT-JAKOB-DISEASE IN SUBJECTS WITH THEPRNP GENE CODON-200 POINT MUTATION, Neurology, 44(9), 1994, pp. 1683-1686
We determined the penetrance of the PRNP 200(Lys) mutation in the larg
e cluster of Creutzfeldt-Jakob disease (CJD) cases among Jews of Libya
n-Tunisian origin living in Israel, utilizing data from 52 carriers wi
th definite or probable CJD and 34 unaffected mutation carriers. A lif
e table analysis was carried out with development of CJD as the end po
int. The probability of developing CJD rose with age, fitting a second
-order regression curve (R = 0.97, p < 0.001). The cumulative penetran
ce reached 50% at the age of 60 and 80% at 80 years. Including seven e
lderly possible CJD patients in the analysis made the penetrance appro
ach 100% by age eighty. The penetrance of the mutation is high, and al
though age is a predominant influencing factor, other factors, such as
gender, may also play a role.