Researchers have linked a shorter lifespan with two common gene changes called variants. The researchers found these common variants near APOE and CHRNA3/5 genes to be associated with lifespan. One copy of either of these two changes to your DNA could shave a year off your life expectancy. People who inherit two copies, one from each parent of both variants could expect to lose about 3.3 to 3.7 years.
APOE gene has been linked to Alzheimer's dementia, high cholesterol, and coronary disease risk. The CHRNA3/5 gene is associated with an increased risk of lung cancer, nicotine dependence, and respiratory problems in smokers. Apparently These variants are pretty common in the population, as more than two-thirds of us will inherit a single copy of one of these DNA changes. And 3 in 1,000 people will inherit two copies of both variants. The variants have age and sex related effects on lifespan. The variant linked to Alzheimer's has a greater impact on older women, while the variation associated with lung disease influences middle-aged men more.
"Although the effect of these genetic variants on lifespan is surprisingly large, it is important to remember that this is only part of the story. Lifestyle has the greatest impact on how long we live and that is under our control." (Peter Joshi)
Original source: http://www.nature.com/ncomms/2016/160331/ncomms11174/full/ncomms11174.html
Related source: http://www.eurekalert.org/pub_releases/2016-03/uoe-igc033016.php