The use of glycomacropeptide in patients with phenylketonuria

Introduction: The deficiency of the phenylalanine hydroxylase, which converts phenylalanine (PHE) into tyrosine (TYR) can cause Phenylketonuria (PKU). If untreated, high PHE blood levels accumulate in the brain and may lead to unalterable intellectual disability, microcephaly, autism, seizures, developmental problems, aberrant behavior, and psychiatric symptoms. Health outcomes for individuals with PKU need nutritional management. Due to the restrictive low-Phe diet in combination with amino acid medical foods (AA-MF) or glycomacropeptide medical foods (GMP-MF) nutrient status in PKU needs attention. GMP is a 64-amino acid glycophosphopeptide derived from κ-casein in bovine milk that shows prebiotic properties. There are no aromatic amino acids in GMP (Phe, Tyr, and Trp) and because of that formulation, it is suitable for the management of PKU and tyrosinemia. The purpose of this review is to evaluate published intervention studies on the use of Glycomacropeptide in Patients with Phenylketonuria by considering its impact on blood PHE control. Methods: PubMed, Scopus, Embase, and Google Scholar electronic databases were searched using the following keywords: ( Caseinoglycomacropeptide OR kappa-casein glycomacropeptide OR glycomacropeptide OR bovine caseinoglycopeptide ) AND ( Phenylketonurias OR PKU ) to December 2019. Results: The main goal in PKU treatments is to promote long-term dietary acceptability and to ultimately enhance the quality of life and metabolic control for individuals with PKU. The results of this study reveal that GMP medical foods provide an alternative to AA formula that may improve palatability, prebiotic, anti-inflammatory and better physiological utilizationwith a lower increase in plasma amino acid levels and decreased ureagenesis after GMP consumption. Conclusion: Greater tolerability and fewer side effects of GMP-MF than AA-MFs, make it a safe and acceptable choice for the nutritional management of individuals with phenylketonuria.

Keywords:

Glycomacropeptide , Phenylketonurias , Metabolic Diseases