Apolipoprotein E in Southern Italy: protective effect of epsilon 2 allele in early- and late-onset sporadic Alzheimer's disease.

Apolipoprotein E (apoE) polymorphism was evaluated in 81 sporadic late onset Alzheimer's disease (LOAD) patients,28 sporadic early-onset Alzheimer's disease (EOAD) and 92 sex- and age-matched healthy controls from Apulia, Southern Italy. ApoE genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism method. The frequency of apoE 14 allele was signi®cantly higher in EOAD patients than in the control group, but not in LOADpatients. Furthermore,EOAD patients carrying 14 allele had lower age at onset ADsymptoms (about 4.5 years). In the whole sample, 14 was associated to AD by an odds ratio of 2.14, while it increased up to 6.55 in,65 years old subjects.Finally, in both ,65 and $65 subgroups of subjects, 12 played a protective role against the development of AD. It is concluded that the geographic decreasing trend of 14 allele and the age at onset may in¯uence the association of apoE polymorphism with sporadic AD in a Southern Italian sample.