Deformaties comes from mutations in the DNA strains of different breeds. When you see people talking about F1, F2 etc they are talking about the generation i.e. F1 is the first generation of combining 2 different strains. It normally takes several generations to breed out those mutations, and typically that doesn't happen much anymore.
With that said, don't stress about them, the newer growth will straighten out as it grows. Normally its one fan leaf or one finger from a leaf, if thats the case don't worry about it. IF all the leaves are showing something then hop on google or here and check it out.