That is never the case. Like finger prints, each and every human being has a different palm/palm lines. The left and the right palm are also different. Even identical twins have different palms/palm lines. Though not scientifically proven but based on my humble experience, I believe that our superconscious, subconscious and conscious mind determines our actions /karma, and temperament which form our palm lines as we grow. That is why one should not see the palm of a child. If there is a sudden/rapid or even a gradual change in the same, then the palm lines also change accordingly.
I hope that in the times to come funds would be allocated to palmistry research so that these trends can be captured and catalogued, thereby giving more credibility to palmistry.
Below I attach the palm pictures of a couple. They could not be more different.