The leucine (7)-to-proline (7) polymorphism in the signal peptide of neuropeptide Y is not associated with Alzheimer's disease or the link apolipoprotein E

Both apolipoprotein E epsilon 4 allele (APOE epsilon 4) and neuropeptide Y (NPY) Pro(7)-variant have been reported to be associated with higher serum levels of total and LDL cholesterol. Since APOE epsilon 4 allele is also a major risk factor for the development of Alzheimer's disease (AD) and the g enetic polymorphism of NPY has not previously been studied in dementing dis orders, we have examined whether a novel polymorphism in a signal peptide o f NPY gene is associated with AD alone or in combination with APOE epsilon 4. A total of 125 sporadic AD cases and 110 control individuals from Finlan d were genotyped for APOE and NPY genes using the polymerase chain reaction and restriction enzyme analysis. The APOE epsilon 4 allele frequency was s ignificantly increased in the AD group compared with controls as expected. Instead, no significant differences were found between sporadic AD patients and controls either in the NPY genotype or allele frequencies or in combin ation with the APOE epsilon 4 allele. We conclude that APOE epsilon 4 allel e represents a strong predictor of risk for AD. (C) 2000 Elsevier Science I reland Ltd. All rights reserved.