COMPARISON OF THE PROTEIN-QUALITY OF DIETETICALLY TREATED PHENYLKETONURIA PATIENTS WITH THE RECOMMENDATIONS OF THE WHO EXPERT CONSULTATION

The protein quality of the diets of phenylketonuria (PKU) children of different ages (3 months, 10 months, 3 years, 8 years, 12 years, 16 ye ars) with low or high phenylalanine (Phe) tolerance was assessed accor ding to the recommendations of the FAO/WHO consultation group [13]. Th e amount of each essential amino acid (AA) per gram dietary protein wa s calculated and compared to the reference. The resultant amino acid s core (AAS) indicated a limited to inadequate biological protein qualit y of the diets in 3-month-old infants (2.2 g protein/kg body weight/da y) and 10-month-old infants (2.0 g protein/kg body weight/day) with a ''high'' Phe tolerance. In all other age groups the AAS was > 100%. Ho wever remarkable imbalances in the AA pattern were apparent. Beginning with the age of 3 years (1.7 g protein/kg body weight/day) the intake of the AA lysine and isoleucine was three or two times higher than re commended. At the age of 8 years (1.4 g protein/kg body weight/day) th e intake of three AA (valine, isoleucine, lysine) was - related to the WHO recommendations - 217%, 229% and 291%. Similar results could be f ound in the age groups of 12 years (1.1 g protein/kg body weight/day) and 16 years (0.9 g protein/kg body weight/day), respectively. These c alculations might help to reconsider the composition of the AA mixture s used in the dietetic treatment of PKU patients.