A Swiss-led research team has identified the largest-ever number of genetic markers – most of which are entirely new to science – that are directly linked to human life expectancy.
The length of a person’s life is largely dictated by their environment – for example, where they live, how rich or poor they are, and whether they smoke and eat a healthy diet. But 20-30% of variation in life expectancy is believed to be under the control of our genome.
Scientists believe that variations at specific locations on DNA sequences called single nucleotide polymorphisms, or SNPs, could hold the key to understanding the genetic side of human lifespan – but only two such markers had previously been identified.
Now, a Swiss-led research team including experts from the Swiss Institute for Bioinformatics (SIB), the Lausanne University Hospital (CHUV), the University of Lausanne (UNIL) and the Swiss Federal Institute of Technology in Lausanne (EPFL) have used an innovative computational approach to identify an unprecedented 16 SNPs associated with lifespan – 14 of which are new to science.
“This is the largest set of lifespan-associated genetic markers ever uncovered,” said Zoltán Kutalik, statistical genetics group leader at SIB in a press statementexternal link.
What are SNPs?
Pronounced ‘snip’, SNPsexternal link are single nucleotide polymorphisms. Simply put, they refer to specific places in a DNA sequence where the molecular composition of the DNA varies in more than 1% of the population. The knowledge that some SNPs are associated with certain diseases allows researchers to assess a person’s genetic predisposition for disease risk by searching their genome for SNPs.
To get their ground-breaking results, Kutalik and his colleagues analysed a dataset of 116,279 individuals from a UK Biobank study, and examined some 2.3 million SNPs.
“We gave priority to variations in DNA known to be associated with illness linked to age, in order to more effectively scan the genome,” Kutalik explained.
The researchers further showed that around one person in 10 carries some configuration of these 16 markers that can cut life short by more than one year compared to the population average.
But it’s not as simple as finding places on DNA molecules that code for a certain lifespan – the research addresses the relationship between genetics and longevity in a more holistic way. For example, most SNPs were found to be associated with multiple risk factors or diseases – such as a propensity for nicotine dependence or a predisposition toward schizophrenia.