Apolipoprotein E Genotype Disclosure May Not Be Harmful
Awareness of status in children of Alzheimer's patients not linked to more anxiety or depression
WEDNESDAY, July 15 (HealthDay News) -- In the adult children of patients with Alzheimer's disease, the disclosure of apolipoprotein E (APOE) genotype does not appear to increase short-term psychological distress even in those who are APOE ε4-positive. But positive status may be associated with a premature decline in memory, according to two studies published in the July 16 issue of the New England Journal of Medicine.
In one study, Robert C. Green, M.D., of the Boston University School of Medicine, and colleagues randomly assigned 162 asymptomatic adults to either receive or not receive the results of their own APOE genotyping. Overall, they found no significant group differences in measures of anxiety, depression, or test-related distress. But they found that test-related distress was lower among patients who learned they were APOE ε4-negative than in those who learned they were APOE ε4-positive.
In a second study, Richard J. Caselli, M.D., of the Mayo Clinic Arizona in Scottsdale, and colleagues followed 317 APOE ε4 carriers and 498 non-carriers for up to 5.3 years. They found that APOE ε4-positive status was associated with a significant age-related memory decline that began before age 60 and accelerated over time.
"Could any societal good or harm result from widespread, on-demand genetic testing for APOE ε4?" ask the authors of an accompanying editorial. "Societal benefit seems unlikely, given that it is not possible to prevent Alzheimer's disease, and available treatments have at best a modest effect on disease progression. Societal harm from testing remains possible, given that Alzheimer's disease is widely regarded as being singularly horrific, although persons with Alzheimer's disease can retain their sense of humor, experience existential joy, and overcome the sum total of so-called negative behaviors that are typically measured in care settings."
Authors of the studies and editorial reported financial relationships with pharmaceutical and medical companies.