Parkinson's patients were genotyped for the apolipoprotein E alleles a
s well as polymorphisms at the apolipoprotein B loci to determine whet
her they were at risk for late onset Alzheimer's disease or coronary d
isease. The Parkinson's patients were at no greater risk for either di
sease than were the control spouses. The frequency for the APOE4 allel
e was 11% compared with the spouses, 10%. Interestingly, 20% of the pa
tients had the 2/3 genotype which may have a protective effect from la
te onset Alzheimer's disease.