Because the two systems share sixty-four numbers, it is easy to assume they are variants of one another. They are not, and the differences are as instructive as the overlap.
Kept from Human Design: the sixty-four positions and their King Wen hexagram numbers; the arrangement of the hexagrams around a zodiacal wheel; the calculation of a personal chart from planetary positions at birth and at a prenatal moment; the pairing of each key with a programming partner, the position opposite it on the wheel, so that the fifty-fifth is paired with the fifty-ninth and the first with the second; and a good deal of the underlying thematic vocabulary, since Rudd taught the earlier system for years before writing his own.
Dropped: the bodygraph itself, with its nine centres and thirty-six channels; the four types and their strategies; authority as a decision-making rule; the defined and undefined distinction and the whole conditioning model built on it; and the prescriptive tone. A Gene Keys reading does not tell anyone to wait for an invitation or to inform before acting.
Added: the Shadow, Gift and Siddhi spectrum; the contemplative method; and a devotional register largely absent from Human Design, which is comparatively dry.
The two systems will therefore give a person the same sixty-four numbers and quite different accounts of what to do with them. Where these entries describe a Gene Key, they describe Rudd's reading; where the corresponding gate is described elsewhere in this atlas, that is Ra Uru Hu's. Both sit on top of a hexagram whose traditional meaning is older than either by a very long margin, and the three layers are best kept visibly distinct.