Genetic association of a cathepsin D polymorphism and sporadic Creutzfeldt-Jakob disease.

Cathepsin D is the most abundant lysosomal and endosomal aspartyl protease; it shows beta and gamma secretase activity in vitro by cleaving the amyloid precursor protein into amyloid beta protein. In recent studies, cathepsin D was co-localized with PrP(Sc), the disease-associated form of the prion disease, and abnormal expression of cathepsin D correlated with tissue damage in brains of sporadic Creutzfeldt-Jakob disease (CJD). To investigate whether a polymorphism at position 224, C224T, on exon 2 of the cathepsin D gene (CTSD) is associated with sporadic CJD in the Korean population. We compared the genotype and allele frequencies at this polymorphism site in 172 sporadic CJD patients with those in 197 healthy Koreans. Our study does not show a significant difference in genotype (p = 0.901) and allele (p = 0.509) frequencies of CTSD C224T between sporadic CJD patients and normal controls. This was the first genetic association study of CTSD in a sporadic CJD population.