[Breast feeding of infants with phenylketonuria].

Five infants with phenylketonuria who received their phenylalanine primarily from breast milk were compared with five other infants with PKU who received infant formula as their primary phenylalanine source. No significant differences between both groups were observed for weight gain, the daily phenylalanine intake, and mean plasma phenylalanine concentrations. This study shows that breast feeding can be continued in young infants with their difficult to predict weight gain and daily changing phenylalanine requirements.