I recall seeing this Google Tech Talk by Steve Hsu on how they are in the process of finding out basically all the additive genes that contribute to intelligence in China at the BGI research institute: https://youtu.be/62jZENi1ed8

They would take roughly a thousand people who are >=3 standard deviations smarter than average and compare their full genomes against people who are of average intelligence. This way they expect to find out all the "easy" genetic determinants of intelligence.