Apolipoprotein E genotype in Spanish patients of Alzheimer's or Parkinson's disease

Blood donors of the Madrid area show a 6% frequency of apolipoprotein E genotype carrying allele ε4. This frequency is smaller than other populations of Caucasian origin. This proportion decreases to 4% in a selected sample of healthy individuals of ages >60 years. The frequency (34%) of the allele ε4 was significantly increased in patients of late onset Alzheimer's disease, similarly to other populations. An earlier age of onset of the dementia is observed in the patients of late-onset Alzheimer's disease carrying the allele ε4. No increased frequency in allele ε4 frequency was found in patients of early-onset Alzheimer's disease. Patients of Parkinson's disease do not show any differences in the frequency of the alleles of apolipoprotein E when compared with healthy individuals.