Genetic susceptibility testing versus family history-based risk assessment: Impact on perceived risk of Alzheimer disease.
OBJECTIVE
We examined how an Alzheimer disease (AD) family history assessment as compared to a risk assessment incorporating the absence of a disease-associated susceptibility allele affected risk perception among adult children with a family history of AD.


METHODS
The REVEAL study is a clinical trial in which adult children of patients with AD were randomized to receive a risk assessment based upon family history alone or family history plus apolipoprotein E (APOE) disclosure. In this analysis, two subsets of women were identified, each of whom received identical 29% lifetime risk estimates of developing AD. One group received a risk estimate that incorporated APOE epsilon4-negative genetic test results (Genotype Group, n = 30), whereas the other received a risk estimate based on family history and gender (Family History Group, n = 36). Six weeks after risk disclosure, we surveyed participants regarding the impact of the risk assessment on their perceptions of AD risk.


RESULTS
73% of the Genotype Group judged their risk to be lower compared to 25% of the Family History Group (P < 0.0001). 67% of the Genotype Group reported lower anxiety about AD, versus 26% of the Family History Group (P < 0.01). 80% of the Genotype Group indicated that the risk information had a positive impact, versus 36% of the Family History Group (P < 0.001). The Genotype Group was less likely to believe that they would develop AD (13% vs. 36%, P < 0.05) and was more likely to report that the risk assessment removed uncertainty about their chances of developing AD (63% vs. 9%, P < 0.0001).


CONCLUSIONS
These data suggest that risk estimates incorporating negative genetic test results affect perceptions of disease susceptibility more strongly than identical estimates based on family history alone.
LaRusse
Susan
S
Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York, USA.
Roberts
J Scott
JS
Marteau
Theresa M
TM
Katzen
Heather
H
Linnenbringer
Erin L
EL
Barber
Melissa
M
Whitehouse
Peter
P
Quaid
Kimberly
K
Brown
Tamsen
T
Green
Robert C
RC
Relkin
Norman R
NR
D000544:Alzheimer Disease / Q000235:genetics; D001057:Apolipoproteins E / Q000235:genetics*; D005190:Family; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005820:Genetic Testing / Q000379:methods; D005838:Genotype; D006801:Humans; D010375:Pedigree; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors
D001057:Apolipoproteins E