Table 1. Participant Characteristics at the Time of Diagnosis With Symptomatic AD.

Characteristic	No. (%) (N = 164)
AAO of AD, mean (SD) [range], y	70.9 (8.3) [46-96]
Women	90 (54.9)
Education, mean (SD) [range], y	15.4 (2.9) [8-29]
Race/ethnicity
Non-Hispanic white	144 (87.8)
African American	19 (11.6)
Asian	1 (0.6)
APOE ε4 allele carriers	110 (67.1)
1 copy (ε2/4, ε3/4)	89 (54.3)
2 copies (ε4/4)	21 (12.8)
Global Clinical Dementia Rating, median (range)	0.5 (0.5-1.0)
Mini-Mental State Examination Score, mean (SD) [range]	25.0 (3.9) [9-30]
Parental AAO of AD, mean (SD) [range], y
Maternal	77.3 (10.4) [39-102]
Paternal	77.5 (10.7) [47-97]

Abbreviations: AAO, age at symptomatic onset; AD, Alzheimer disease.