[Treatment of phenylketonuria. About twenty-one cases (author's transl)].

A homogeneous group of 21 phenylketonuric patients, diagnosed neonatally, were put on a restricted diet to maintain phenylalaninemia between 0.30 and 0.55 mumol/ml (5-9 mg/100 ml). The same medical team has followed the developmental course of patents, who are presently between 2 and 8 years of age. Physical growth and mental development are analysed according to the quality of the control of phenylalaninemia and to the phenylalanine tolerance. Conclusions compared to those of other groups point out some problems which are not yet resolved: what is the optimal phenylalanine level to be reached in treated patients and the age to which should be phenylalanine restricted diet be terminated.