Board Thread:Fun and Games/@comment-24810520-20151204182918/@comment-25296247-20170208193718

Well, possibly... Quirks are DNA mutations, so I suppose they could repeat, just like genetic diseases...

But on the other side, I think that their properties would be far more complicated than genetic diseases, so my opinion then is that multiple people can have similar Quirk (either by coincidence -very rare- or because of biological congeniality - like Asui's family or Shouto's heritage), but no two people can be born with the exactly same Quirk.