I Have Two Granddaughters Ages 6 & 11 Who Were

I have two granddaughters ages 6 & 11 who were diagnosed with Phenylalanine a few years ago. it's a catch 22 with the oldest one because she also has Diabetes 1, which she is supposed to eat lots of protein for, (oposite for Phenylalanine). Doctors want to put them on medication, which has bad side effects and costs $10,000.00 per month for each child. Are there any natural treatments that are available for this?