Large neutral amino acids in the treatment of PKU: from theory to practice.
Notwithstanding the success of the traditional dietary phenylalanine restriction treatment in phenylketonuria (PKU), the use of large neutral amino acid (LNAA) supplementation rather than phenylalanine restriction has been suggested. This treatment modality deserves attention as it might improve cognitive outcome and quality of life in patients with PKU. Following various theories about the pathogenesis of cognitive dysfunction in PKU, LNAA supplementation may have multiple treatment targets: a specific reduction in brain phenylalanine concentrations, a reduction in blood (and consequently brain) phenylalanine concentrations, an increase in brain neurotransmitter concentrations, and an increase in brain essential amino acid concentrations. These treatment targets imply different treatment regimes. This review summarizes the treatment targets and the treatment regimens of LNAA supplementation and discusses the differences in LNAA intake between the classical dietary phenylalanine-restricted diet and several LNAA treatment forms.
van Spronsen
Francjan J
FJ
Department of Pediatrics, Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands. f.j.van.spronsen@bkk.umcg.nl
de Groot
Martijn J
MJ
Hoeksma
Marieke
M
Reijngoud
Dirk-Jan
DJ
van Rijn
Margreet
M
D021542:Amino Acids, Neutral / Q000627:therapeutic use*; D000818:Animals; D019587:Dietary Supplements; D005526:Food, Formulated; D006801:Humans; D008962:Models, Theoretical; D010661:Phenylketonurias / Q000178:diet therapy*; D011364:Professional Practice; D011908:Rationalization
D021542:Amino Acids, Neutral