THE CONSORTIUM TO ESTABLISH A REGISTRY FOR ALZHEIMERS-DISEASE (CERAD).6. FAMILY HISTORY ASSESSMENT - A MULTICENTER STUDY OF FIRST-DEGREE RELATIVES OF ALZHEIMERS-DISEASE PROBANDS AND NONDEMENTED SPOUSE CONTROLS

Although familial factors in Alzheimer's disease (AD) are well establi shed, uniform family-history assessment in genetic and epidemiologic s tudies of AD is needed to reconcile the divergent estimates of the cum ulative risk of this illness among relatives of AD probands. To answer the need, the Consortium to Establish a Registry for Alzheimer's Dise ase (CERAD) has developed a standardized Family History Assessment of AD to identify the presence of AD, Parkinson's disease (PD), and Down' s syndrome (DS) in family members. This paper describes the use of thi s new assessment instrument in 118 patients with AD (estimated mean ag e at onset [+/-SD] = 64.5 +/- 7.7 years) and their nondemented spouses who were enrolled in 11 different CERAD sites in the U.S. The first-d egree relatives of the probands with AD had a significantly greater cu mulative risk (p < 0.005) of AD or primary progressive dementia (24.8% ) than did the relatives of spouse controls (15.2%). Furthermore, the cumulative risk for this disorder among female relatives of probands w as significantly greater than that among male relatives. There were no differences between the families of probands and controls for the num bers of affected first-degree relatives with PD or DS. This is the fir st reported multicenter family-history study of AD, and it supports ea rlier reports of familial factors in AD and indicates a higher risk to female relatives of AD probands. The CERAD Family History Assessment instrument may be useful for further multicenter and epidemiologic stu dies designed to delineate familial factors associated with AD.