The patients who are classified as in normal condition without dementia will be diagnosed to have Alzheimer's disease in the next year with a probability ranging from 2.6% (Age = 55, no APOE-4 allele) to 21.1% (Age = 85, two APOE-4 alleles), depending on the patient's age and APOE-4 allele number. This evidence concerns the gene APOE and Alzheimer disease.