The Fourth 'R' (1959)

He was five years old, and he might be the smartest human being on Earth . . .
 
Terrifically suspenseful and readable tale of a small boy artificially made super-intelligent by scientists. He escapes his keepers and uses his superior brain to evade authorities and get along in the adult controlled world. If you liked James Patterson's "When the Wind Blows" and sequels, you'll like this original, tightly written suspense novel even better.