All of the GM products are made to be "nutritionally similar" to the same product family. While they are similar they do at times cause many problems in the system.
I remember about ten years ago that there was a small percentage of young girls in PR that had early breast development. If I remember correctly it was tied to some phthalic acid that the girls were thought to be receiving from cows milk who were eating GM crops. Plastics were thought to play some role.