BBC News website meets the man who has helped families to have genetically-matched babies to treat sick siblings.
Dr Yury Verlinsky was amongst the first in the world, and the first in the US, to introduce chorionic villus sampling (CVS) – a way to diagnose conditions while babies are still in the womb.
He then helped devise a way to diagnose conditions in test-tube babies before they are transferred into the womb.
This shot him to fame when a family used the technique, called PGD, to have a baby whose cord blood could save the life of their other child who was sick with Fanconi anaemia.
Read the BBC report here.