Image of an indigo child via Wikipedia
Psychic children are also known as indigo children and crystal children. They posses mysterious paranormal powers such as clairvoyance, clairaudience and future prediction.
Medical field has no clues for this skill.
In my family, I know of a person who at his very young age of just 6, used to solve complex mathematical problems. Yes, he was a math prodigy.
Some rare psychic children are also empowered with clairsentinence which can help feel the sense of feelings of others. This is truly a phenomenal paranormal ability indeed.