Imagine you could live for two lifetimes. Would you want to? How would it change you and those you love? What would you do with all those extra years? What second chances might you get? Would this be a blessing or a curse?

This world is an alternative version of our own. Except in this world, a minority of people are discovered to have Extended Life Syndrome (ELS). The condition might give an "Elser" two decades in their thirties, two in their forties, double the time in their fifties, and so on. Little is understood of the biological factors that govern ELS except that it affects a random selection of people. It is the ultimate lottery of genetics, crossing class, race, culture and gender.

And if a simple test existed to check your DNA for this double life, would you take it? Would you want to know?

Now think again. Would you?

An Afonica production for BBC Radio 4