Non-replication of association between cathepsin D genotype and late onsetAlzheimer disease

In two recent studies from Germany, a strong association was found between the allelic variant T of the amino acid substitution encoding polymorphism 224 C/T (A38V) in exon 2 of the cathepsin D gene (CTSD) and late onset Alzh eimer disease (AD). Other studies from Europe and the USA revealed ambiguou s results. Therefore, we performed an independent association study on CTSD and AD in a sample of 324 Caucasian patients from Germany, Switzerland, an d Italy with late onset AD, and 302 nondemented controls. We could not conf irm an association between CTSD genotype and AD, although there was a sligh t but not significant increase in frequency of the T allele and T carrier s tatus in AD. Post hoc data analyses suggested that there might be a stronge r effect of CTSD genotype on AD risk in males, and an interaction between C TSD and APOE genotypes in males but not females. (C) 2001 Wiley-Liss, Inc.