Melissa Barber Butson

Disclosure of APOE Genotype for Risk of Alzheimer's Disease

BACKGROUND The apolipoprotein E (APOE) genotype provides information on the risk of Alzheimers disease, but the genotyping of patients and their family members has been discouraged. We examined the effect of genotype disclosure in a prospective, randomized, controlled trial. METHODS We randomly assigned 162 asymptomatic adults who had a parent with Alzheimers disease to receive the results of their own APOE genotyping (disclosure group) or not to receive such results (nondisclosure group). We measured symptoms of anxiety, depression, and test-related distress 6 weeks, 6 months, and 1 year after disclosure or nondisclosure. RESULTS There were no significant differences between the two groups in changes in time-averaged measures of anxiety (4.5 in the disclosure group and 4.4 in the nondisclosure group, P=0.84), depression (8.8 and 8.7, respectively; P=0.98), or test-related distress (6.9 and 7.5, respectively; P=0.61). Secondary comparisons between the nondisclosure group and a disclosure subgroup of subjects carrying the APOE epsilon4 allele (which is associated with increased risk) also revealed no significant differences. However, the epsilon4-negative subgroup had a significantly lower level of test-related distress than did the epsilon4-positive subgroup (P=0.01). Subjects with clinically meaningful changes in psychological outcomes were distributed evenly among the nondisclosure group and the epsilon4-positive and epsilon4-negative subgroups. Baseline scores for anxiety and depression were strongly associated with post-disclosure scores of these measures (P<0.001 for both comparisons). CONCLUSIONS The disclosure of APOE genotyping results to adult children of patients with Alzheimers disease did not result in significant short-term psychological risks. Test-related distress was reduced among those who learned that they were APOE epsilon4-negative. Persons with high levels of emotional distress before undergoing genetic testing were more likely to have emotional difficulties after disclosure. (ClinicalTrials.gov number, NCT00571025.)

Incorporating ethnicity into genetic risk assessment for Alzheimer disease: The REVEAL study experience

Purpose: To describe how investigators in a multisite randomized clinical trial addressed scientific and ethical issues involved in creating risk models based on genetic testing for African American participants.Methods: The following informed our decision whether to stratify risk assessment by ethnicity: evaluation of epidemiological data, appraisal of benefits and risks of incorporating ethnicity into calculations, and feasibility of creating ethnicity-specific risk curves. Once the decision was made, risk curves were created based on data from a large, diverse study of first-degree relatives of patients with Alzheimer disease.Results: Review of epidemiological data suggested notable differences in risk between African Americans and whites and that Apolipoprotein E genotype predicts risk in both groups. Discussions about the benefits and risks of stratified risk assessments reached consensus that estimates based on data from whites should not preclude enrolling African Americans, but population-specific risk curves should be created if feasible. Risk models specific to ethnicity, gender, and Apolipoprotein E genotype were subsequently developed for the randomized clinical trial that oversampled African Americans.Conclusion: The Risk Evaluation and Education for Alzheimer Disease study provides an instructive example of a process to develop risk assessment protocols that are sensitive to the implications of genetic testing for multiple ethnic groups with differing levels of risk.

A randomized noninferiority trial of condensed protocols for genetic risk disclosure of Alzheimer's disease.

Conventional multisession genetic counseling is currently recommended when disclosing apolipoprotein E (APOE) genotype for the risk of Alzheimers disease (AD) in cognitively normal individuals. The objective of this study was to evaluate the safety of brief disclosure protocols for disclosing APOE genotype for the risk of AD.

A randomized controlled trial of disclosing genetic risk information for Alzheimer disease via telephone

PurposeTelephone disclosure of genetic test results can improve access to services. To date, studies of its impact have focused on return of Mendelian risk information, principally hereditary cancer syndromes.MethodsIn a multisite trial of Alzheimer disease genetic risk disclosure, asymptomatic adults were randomized to receive test results in person or via telephone. Primary analyses examined patient outcomes 12 months after disclosure.ResultsData from 257 participants showed that telephone disclosure occurred 7.4 days sooner and was 30% shorter, on average, than in-person disclosure (both P < 0.001). Anxiety and depression scores were well below cutoffs for clinical concern across protocols. Comparing telephone and in-person disclosure protocols, 99% confidence intervals of mean differences were within noninferiority margins on scales assessing anxiety, depression, and test-related distress, but inconclusive about positive impact. No differences were observed on measures of recall and subjective impact. Subanalyses supported noninferiority on all outcomes among apolipoprotein E (APOE) ɛ4–negative participants. Subanalyses were inconclusive for APOE ɛ4–positive participants, although mean anxiety and depression scores were still well below cutoffs for clinical concern.ConclusionTelephone disclosure of APOE results and risk for Alzheimer disease is generally safe and helps providers meet demands for services, even when results identify an increased risk for disease.