There was no significant difference between groups in age, gender, years of education, retest interval, premorbid IQ, and the number of APOE e4 alleles (all p-values of >0.1), while groups differed significantly in YECO (F = 4.84, df=3/59, p < 0.01, η2 = 0.20) and global cognition assessed by MMSE (F = 17.96, df = 3/42, p < 0.001, η2 = 0.56) in relation to the progression of AD. The gene discussed is APOE; the disease is Alzheimer disease.