Researchers have uncovered a new gene variant that appears to counteract the risk of Alzheimer's disease posed by APOE4, HealthDay News reports.
A Stanford University-led team conducted a genetic association study that drew upon more than 540,000 participants, including nearly 68,000 individuals with Alzheimer's disease, more than 28,000 individuals with a close relative who has Alzheimer's disease, and about 340,300 unaffected individuals. As they report in JAMA Neurology, the researchers uncovered two missense variants that were both associated with a more than two-fold reduction in risk of Alzheimer's disease. One variant, R251G, is coinherited with ε4 on the APOE gene and lessens the risk of Alzheimer's disease associated with ε4. The other variant, V236E, is coinherited with APOE ε3 and also lessens disease risk, confirming previous work.
Both variants affect the carboxyl-terminal portion of apoE, suggesting to the researchers that that region might have a key role in Alzheimer's disease pathogenesis. "If we can better understand how the mutations are mitigating risk, this may open the door to possible treatment targets and/or biology to target for therapy development," Heather Snyder, vice president of medical and scientific relations at the Alzheimer's Association, tells HealthDay.