THURSDAY, March 14, 2019 (HealthDay News) -- Having affected first-degree, second-degree, or third-degree relatives (FDRs, SDRs, and TDRs) is associated with an increased risk for Alzheimer disease (AD), according to a study published online March 13 in Neurology.
Lisa A. Cannon-Albright, Ph.D., from the University of Utah School of Medicine in Salt Lake City, and colleagues used a population resource, including genealogy of Utah pioneers from the 1800s, linked to Utah death certificates to estimate relative risk for AD based on specific family history constellations.
The researchers found that the risk for AD was significantly increased with having any affected first-degree relatives (one or more FDRs: relative risk [RR], 1.73; two or more FDRs: RR, 3.98; three or more FDRs: RR, 2.48; four or more FDRs: RR, 14.77). Even in the presence of affected FDRs, affected SDRs correlated with an increased risk (one FDR with two SDRs: RR, 21.29). Increased risk was also seen in TDRs (no FDR, no SDR, three or more TDRs: RR, 1.43). There was mixed evidence for differences in risk based on maternal versus paternal inheritance, with higher risks for men than women with equivalent family history.
"More and more, people are increasingly seeking an estimate of their own genetic risk for Alzheimer's disease," Cannon-Albright said in a statement. "Our findings indicate the importance of clinicians taking a person's full family history that extends beyond their immediate family members."
Several authors disclosed financial ties to the pharmaceutical industry.