Abstract
Few cases of premature infants with classical phenylketonuria (PKU) have been reported. Treatment of these patients is challenging due to the lack of a phenylalanine (Phe)-free amino acid (AA) solution for parenteral nutrition. A boy born at 27 weeks of gestation with a weight of 1000 g was diagnosed with classical PKU on day 7 because of highly elevated Phe level at newborn screening (2800 µmol/L). Phe intake was suspended for 5 days and during this time intravenous glucose and lipids as well as small amounts of Phe-free formula through nasogastric tube were given. Because of insufficient weight gain attributable to deficiency of essential AA, a Phe-reduced, BCAA-enriched parenteral nutrition was added to satisfy AA requirements without overloading in Phe. Under this regimen, the boy started to gain weight, Phe plasma levels progressively reduced and normalized on day 19. At the age of 40 months, the patient shows normal growth parameters (height 25th percentile, weight 25–50th percentile, head circumference 50th percentile) with a normal result for formally tested psychomotor development (WPPSI-III). The good outcome of the patient in spite of over 2 weeks of extremely high Phe concentrations suggests that the premature brain may still have enough plasticity to recover. Lacking a Phe-free intravenous AA solution, successful management of premature infants with PKU depends on the child's tolerance of enteral nutrition. Although the coincidence of PKU and prematurity is rare, there is strong need for the development of an appropriate Phe-free amino acid solution for parenteral nutrition especially in case of gastro-intestinal complications of prematurity.
Highlights
Phenylketonuria (PKU; OMIM #261600) is an autosomal recessive inherited defect of pheny-Correspondence: Diana Ballhausen, Division de Pédiatrie Moléculaire, CHUV, CI 02-35Av
The little reported experience shows that the management of classical PKU in preterm infants is not yet established. Adequate treatment of these patients is complicated by two problems: the lack of a Phe free amino acid solution for parenteral infusion, and the lack of reference values for safe Phe plasma concentrations related to gestational age
In the absence of a specific Phe-free parenteral nutrition, amino acid solutions used for hepatic disorders are more appropriate than classical amino acid solutions for prematurity, because of their high content of essential amino acids and relatively low amount of aromatic amino acids
Summary
Phenylketonuria (PKU; OMIM #261600) is an autosomal recessive inherited defect of pheny-. Acknowledgments: we thank our colleagues from the neonatal care unit for excellent follow-up of the patient, Beat Thöny, Clinical Chemistry, Kinderspital Zürich for molecular analysis and SHS Gesellschaft für klinische Ernährung mbH and Milupa Metabolics GmbH, Germany for the support of nutritional counseling. Few cases of premature infants with classical phenylketonuria (PKU) have been reported. Treatment of these patients is challenging due to the lack of a phenylalanine (Phe)-free amino acid (AA) solution for parenteral nutrition. Phe-free intravenous AA solution, successful management of premature infants with PKU depends on the child’s tolerance of enteral nutrition. The coincidence of PKU and prematurity is rare, there is strong need for the development of an appropriate Phe-free amino acid solution for parenteral nutrition especially in case of gastro-intestinal complications of prematurity. Nutrition Unit, 3Developmental Unit, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland ci
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
