Fancy living to 100? Your chances are boosted if you carry protective variants of four newly discovered genes. They are:
鈥� ABO Determines blood group
Advertisement
鈥� CDKN2B Helps regulate cellular life cycles
鈥� SH2B3 Has been shown to extend lifespan in fruit flies
鈥� One of the HLA genes, which are involved in how the immune system recognises the body鈥檚 own cells
Uncovered by searching the genomes of centenarians, the genes join APOE, which influences the risk of Alzheimer鈥檚, as the bits of our genome most clearly associated with longevity. They鈥檙e tantalising clues to uncovering the mystery of why we age, and could help us find ways to prevent age-related diseases.
鈥淚鈥檓 motivated because I really don鈥檛 understand why we get old,鈥� says lead author at Stanford University. 鈥淲hat is the clock that gives us 80?鈥�
Gene trawl
suggest that genetic make-up has a significant influence on lifespan. It is common for siblings of the same family to live very long lives. 鈥淭hose sorts of things argue persuasively that about 20 per cent of lifespan is genetic, possibly more for living to be extremely old,鈥� says Kim.
But which genes are responsible? Several studies have looked for variations that are more or less common in long-lived people, but until now, only APOE consistently came up.
For example, in 2014, Kim published a study comparing the genomes of 17 supercentenarians 鈥� people aged 110 and over 鈥� with those of the general population. The study included a 116-year-old woman who was the world鈥檚 oldest living person at the time. He hoped the supercentenarians might share a rare variant that explained their tenacity but nothing turned up, and the media announced the .
Zoning in
This time Kim had more success. He expanded his search to include 800 people over 100 and about 5000 over 90 鈥� but narrowed the focus to genes known to influence age-related diseases. His idea was that this would point the way towards common mechanisms associated with ageing.
He was right. Of the four new genes and APOE that showed up in the search , each has a variant that can reduce or increase a person鈥檚 chances of reaching 100. The variations are common in the general population, but centenarians seem to have fewer 鈥渂ad鈥� variants.
鈥淚t鈥檚 an elegant and refreshing approach,鈥� says Henne Holstege from the VU University Medical Center in the Netherlands, who also studies supercentenarians.
Lifespan prediction
鈥淚t鈥檚 the first time someone has shown that particular disease [variants] are depleted in centenarian populations,鈥� says of the Spanish National Cancer Research Centre in Madrid. 鈥淚t points to important processes that are impaired in ageing populations.鈥�
Predicting people鈥檚 lifespan based on their genes remains a distant dream, however. 鈥淚 don鈥檛 think we鈥檒l ever have concrete genetic determinants that will allow us to say this person is going to live to be 100-odd,鈥� says Cash.
But Kim is convinced that longevity is strongly influenced by genetics, and believes that the search will lead to answers. 鈥淭he amount of data is going up extremely fast and the way we look at the data is improving all the time,鈥� he says. 鈥淚鈥檓 optimistic that in our lifetime or our children鈥� lifetime, there are going to be amazing scientific advances that could change how we think about longevity.鈥�
Journal reference: PLOS Genetics, DOI:
(Image: REUTERS/Juan Carlos Ulate)
