I know that the Metabolic Nutritionists in the US are working on creating standards across the clinics. At our clinic, we are told that levels should be between 120 and 360. We aim to keep Molly, who is 10 and has CPKU, between 120 and 240.
The system we use for counting protein/phe is different from yours. We count mg of phe and pretty much everything Molly eats — including all fruits and veggies. It is a pain but gives us a better sense of exactly how much phe she is getting (Again, she has CPKU so she likely needs tighter control).
Is your son getting enough protein? Molly gets over 65 gm from her formula and another 8 gm from food. We were always told that since the protein from the metabolic drink is synthetic and so broken down, the body cannot utilize it as efficiently as a more natural whole protein. As a result, some of it is lost in the urine before the body can use it. Because of this, our kids actually need more protein than the USDA standards recommend. If the body is not getting enough protein (or calories), it is pretty resourceul and will become catabolic, breaking down muscle in the body to get what it needs. Since this muscle is high in protein, the levels go higher.
Sometimes if our kids do not get enough calories and protein their phe levels rise and it appears that their daily phe/protein allowance is lower than it actually is.
Best of Luck!
Here in Canada we follow the same guidelines- we are also trying to keep between 120-360. I personally like to keep my daughter's levels a bit lower (between 120-260) but my doctors/dieticians/specialists do not seem to think that is medically necessary but I've found that my daughter (age 1) is a different child with higher levels- the higher the level the less sleep she gets, the more irritable she is and she doesn't seem to progress as well.
We will never introduce meat or dairy (or regular grains) to our daughter if we can help it. She is also CPKU and we feed her specialty foods and fruits and some veggies (although everything is weighed /measured/counted) . I'm not sure if it matters if it is mild pku or hyper as they are treated the same- for my daughter her first level was 377 and then at 7 days it was 1100.
She is now transitioning to her toddler formula which has more protein than the baby formula so at this moment i'm not exactly sure her total daily protein (she gets a bit of baby formula, a bit of toddler formula and a bit of breastmilk each day ) but in solid foods she is getting 80mg phe per day.
I would agree, don't get too worried about what they are calling it. Jacob was classed HyperPhe from a couple weeks old, until December. Then it changed to Mild PKU our understanding it was because his levels rose over 600 quite rapidly with the introduction of simple solids (rice cereal). The only real difference I can tell, is the name they call it.
Treatment has pretty much been the same as it was before. I do know another HyperPhe kid, she doesnt have to count veggies, where we do. But that could also be variations of treatment plans from clinic to clinic.
The range for our center, is the same as Clenk 120-360. This has been a terrible season of colds for Jacob, so many have been in the higher range. Hoping Spring will help in keeping those numbers down. Him being sick REALLY affects his levels.