Imagine a future where an online dating app doesn’t just match you to potential partners who meet your preferences for age, height and fondness for pinot noir, but to those with whom you’re genetically compatible. Not so much people you’re likely to have physical chemistry with – apps that make dubious claims to do that on the basis of a cheek swab already exist – but those with whom you won’t pass on a devastating genetic disease to your children.

It’s not sexy stuff; certainly not first-date conversation. Most people only discover that they’re among the four per cent who carry the same recessive genetic mutation for a rare condition, such as cystic fibrosis or Tay-Sachs, as their partner when their baby is born with it – or dies from it.

True, couples could find out their genes don’t mix after they’ve decided to have a baby and before they start trying – but how heartbreaking would that be, once they’re already in love? Far simpler never to meet in the first place, and simply to pick from the other 96 per cent with whom they can mate with abandon.

This is the vision of maverick Harvard geneticist Professor George Church. Or rather, it’s one of the least outlandish of his ideas, compared to some of the others he has in the pipeline: genetically modifying pigs to grow organs fit for human transplant; reversing ageing in dogs, as a prelude to doing the same in humans; resurrecting the woolly mammoth. Oh, and rewriting the entire genetic code of human life.