Listener Vivek got in touch with a question about a rare genetic disease his son has, called FOXG1 Syndrome. In fact, it's so rare - and so newly-discovered - that only about six hundred people in the world have been diagnosed. Kids with FOXG1 have severe developmental delays; in Vivek's words, "everything that can go wrong - it's gone wrong with him." But the parents of FOXG1 children have been unusually tenacious when it comes to shaping the course of science. In this programme we meet those people blurring the line - metaphorically speaking - between the brain and the heart.