HEIDI DOUGLASS | h.douglass@unsw.edu.au
Five variants in the genetic code were identified as significant for exceptional longevity in a recent study by researchers from the Centre for Healthy Brain Ageing (CHeBA) at UNSW Sydney.
The study, published in the journal Mechanisms of Ageing and Development, involved a review of existing findings and, for each variant identified, a meta-analysis was undertaken using data from at least three independent studies, including CHeBA’s Sydney Centenarian Study.
Exceptional longevity, defined as exceeding the average life expectancy, is affected by a combination of genetic and environmental factors. Many individuals who have lived to an exceptional age, have delayed or escaped age-related disease, and represent a unique human model for studying the determinants of successful ageing. Favourable lifestyle choices, such as increased physical activity, eating a healthy diet and not smoking, as well as improved healthcare and access to better medicines have contributed to an increase in lifespan. Previous family and twin studies have shown that genetics plays a role in longevity, however genetic studies examining exceptional longevity have been inconclusive.
Lead author and CHeBA PhD student Mary Revelas said polymorphisms, or variations in the genetic code, of five genes were identified as exceptional longevity variants in studies of people aged 85 and over versus controls: ACE rs4340, APOE ε2/3/4, FOXO3A rs2802292, KLOTHO KL-VS and IL6 rs1800795.
Ms Revelas said that while a significant association was observed for exceptional longevity, the effects were generally modest with no single polymorphism being a major contributor.
“Our findings suggest that many genes of small influence play a role in exceptional longevity, which is consistent with results for other polygenic traits, or traits controlled by multiple genes, such as height,” said Ms Revelas.
Senior author and Leader of CHeBA’s Genetics & Epigenomics Group, Dr Karen Mather, said “the findings provided insights for a range of future studies related to successful ageing.”
“Our results also suggest that genes related to cardiovascular health may be implicated in exceptional longevity,” said Dr Mather.
The authors said one limitation of the findings was a lack of studies including non-Caucasian participants and few studies had investigated gender differences. They said future longevity studies should examine different ethnicities and sex differences to improve our understanding of the role of genetic variants in exceptional longevity.
Mary Revelas is a CHeBA PhD student.
