Hi Danielle (I have alittle sister named Danielle!) nAnyway, wow I never realized there were so many others with siblings with PKU. Danielle do you have alot of other siblings? My dietian told me its more common for there to be more the one kid with PKU in big familys. I have an 8 year-old sister (Erica) with PKU aswell and then 4 sisters and a brother without PKU.