To the original poster from Korea. I have classic PKU and I'm currently living in Japan. USA, from my experience can be hit or miss with PKU expense, with some states covering the cost of supplements and in some cases, food, but others covering hardly anything. If you do decide to go there do some research into the states that are likely to help you. The insurance thing is an obstacle, but getting into the U.S can sometimes be trickier! I hear Nebraska has decent coverage for metabolic diseases. If you're in Korea, you might research Japan too. It is also very rare here from what I am finding out and I am also currently on the look out for doctors in the Kanto area who specialize or who can assist in monitoring and also recommend places within Japan to get dietary foods and formula from. I wish you and your family all the best in your search. I have not tried Kuvan myself yet, primarily because I was just about to finish work in the United States and the cost put me off. I may look into it in Japan.. I heard some early testing or developing was done here…I might be wrong, but hey, everyday you learn something new, right?