It was true throughout the Kingdom that people liked to avoid having problems. It was also true that people wanted to have children, and children could cause enough problems to frustrate even the most patient. When people thought of children like the Lightning Kid, many thought they would have simply too many problems or problems that were too great, and so they sought to use tests to avoid having children like him.
Earlier tests were not as popular, since they were somewhat dangerous put the child at (a slight) risk, regardless of the result of the outcome. When better, less risky tests were invented, many rejoiced at the opportunity to make reasoned, informed decisions, and the test (as near as anyone was willing to discuss it) was considered to be 99% accurate. The King was himself a big advocate of reason and information, so he sought to make a little demonstration at court.
Once the court was gathered, he had his servants bring out a display of shells.
"Each of these shells, represent an instance of a test to determine whether a child will be born with the same condition as your Prince, The Lightning Kid. There are 100 of them, and one of them is false - the result is incorrect. Any decisions made based on that one test will be misinformed."
The King turned to the other side of the room, and waved in servants with more shells.
"These shells represent births. There are 529 of them and one of them is a child with the same condition as the Lightning Kid. I've read that the chance of having such a child is as high as 1 in 300, and as low as 1 in 700, so I've picked a number somewhere in between. If every one of these births had been tested, there would have been at least 5 incorrect results.
While a child like the Lightning Kid will almost definitely have trouble learning and understanding more difficult concepts, problems with the heart, with growth, with digestion and the rest are all only possibilities. And these same problems can crop up in other children - those that would pass these tests that are being celebrated."
He paused, and made sure that he had the audience's undivided attention.
"Let me be clear: if you expect your child to be perfect, if you aren't prepared to deal with at least some health issues, big or small, short or long-term - then you are not prepared to have children. Perhaps that would be a better test."