I cannot search for BH4 (because it says the string is too short, which makes it IMPOSSIBLE to search for SNPs and interesting molecules here) so I am starting a new topic. I have 3 genes that cause it to be hard to make BH4 and for me to use it up faster. BiancaS who has most of the same genes I have (18 defects) was found to be low BH4 and put on kuvan. I tested my father who is a kidney dialysis patient and he has NO DISCERNABLE BH4. This is technically PKU but dialysis must be taking out some of the phenylalanine (it takes out 30g of protein each dialysis session). From biochemistry, BH4 is REQUIRED to make urea! Yet no kidney doctor I have asked (I have asked EIGHT) has ever heard of it. Further, I cannot find a doctor that knows what this is and even cares that my Dad has none. I wanted to clue all of you in who have BH4 issues that this can effect your ability to pee productively. I also wanted to see if anyone knows anything new about BH4. And lastly, wondered what kind of doctor might have a clue about BH4?