The Effects of CGMP in Children and Adults With PKU

Inclusion Criteria: * PKU patient diagnosed on newborn screening (NBS). * \> 50% of protein intake from protein substitutes. * (CHILDREN) Dietary intake of ≤ 1000 mg Phe from natural protein or ≤20 g natural protein inclusive of fruit and vegetables per day. * (ADULTS) Dietary intake of ≤ 1500 mg Phe from natural protein or ≤ 30 g natural protein inclusive of fruit and vegetables per day. * (CHILDREN) Three out of the last four consecutive Phe measurements within the target range (≤360 µmol/L in patients aged 4-12 years). * (ADULTS) Two out of the last four consecutive Phe measurements within the target range (≤600 µmol/L for adults). * Male or female aged 4-12 years or 18 years and over. * Early and continuously treated. Adherent to their prescribed PKU diet consisting of a protein-restricted diet and free AA based protein substitute. * Otherwise in good general health as evidenced by medical history. * Able to provide written informed consent (patient or parent/guardian). * Able to comply with the study protocol and take study product according to the opinion of the PI. * Protein substitute intake provided by L-amino acid supplements only. * (ADULTS) No studies have been done in pregnant women. To ensure patients safety, female patients of childbearing potential must have a negative pregnancy test prior to completing the screening procedures. * (ADULTS) All female patients of childbearing potential and sexually mature males should be willing to use a medically accepted met…