Abstract
The aim of this study was to evaluate the influence of early termination of dietary treatment in phenylketonuria by following the patients' mental development.
Three groups of patients have been evaluated: Group I — 22 classical PKU cases with a mean treatment period of 4 years and 8 months; Group II — 10 cases of classical PKU with a mean treatment period of 2 years 4 months; Group III — 5 PKU variants treated on average for 3 years and 8 months.
The mean period of observation after dietary discontinuation was form 4 to 6 years.
Evaluation of development and further progress of PKU patients after terminating the diet was based on the following parameters: clinical symptoms, selected biochemical examinations, scores of mental development, behaviour and school achievements, and EEG examination.
Detailed analysis of the data revealed a direct relationship between the long-term results of treatment and the age of starting treatment, even in the range of the first three months of life, and also the quality of dietary control and the period of treatment.
Three significant changes emerged after discontinuation of the diet: 1) Decreasing intelligence quotients in most patients with classical PKU. 2) Difficulties in adaptation and school achievements in these patients. 3) Large number of EEG abnormalities after termination of the diet.
These findings in classical PKU patients after discontinuation of the diet reveal that 5 year's dietary treatment is too short for effective therapy in classical PKU.
Normal mental development and good school achievements in PKU variants (hyperphenylalaninaemia) with a treatment period of 31/2 years suggest that in this condition the period of dietary treatment can possibly be shorter than in classical phenylketonuria.
Similar content being viewed by others
References
Bartholomé, K., et al.: Determination of phenylalanine hydroxylase activity in patients with phenylketonuria and hyperphenylalaninemia. Pediat. Res. 9, 899–903 (1975)
Bickel, H.: Eight Conference of Collaborative Study of Children Treated for Phenylketonuria. Soteline, Nevada, USA, February 28–29 (1972)
Brown, E. S., Warner, R.: Mental development of phenylketonuric children on or off diet after age six. Psychol. Med. (1975)
Cabalska, B., et al.: Tentative criteria for terminating the low-phenylalanine diet in PKU. Proceedings of the Third Congress of the International Association for the Scientific Study of Mental Deficiency, pp. 548–551. The Hague, Netherlands: Polish Medical Publishers 1973
Cabalska, B., et al.: Unpublished data
Clayton, B., et al.: Biochemical and EEG study in phenylketonuric children during phenylalanine tolerance tests. Arch. Dis. Childh. 41, 217, 267–272 (1966)
Editorial: The duration of treatment of phenylketonuria. Lancet 1974 I, 917–972
Frankenburg, W., et al.: Behavioral consequences of increased phenylalanine intake by phenylketonuric children: a pilot study describing a methodology. Amer. J. Ment. Defic. 77, 5, 524–532 (1973)
Hackney, J. M., et al.: Phenylketonuria: mental development, behaviour and termination of low phenylalanine diet. J. Ped. 72, 5, 646–655 (1968)
Hanley, W. B., Linsao, L.: Termination of PKU dietary therapy in 62 patients. Pediat. Research 7, 4, 383–383 (1973)
Horner et al.: Termination of dietary treatment of phenylketonuria. New Engl. J. Med. 266, 79, 1–3 (1962)
Hudson, P. F.: Termination of dietary treatment of phenylketonuria. Arch. Dis. Childh. 42, 22, 198–200 (1967)
Johnson, Ch. T.: What is the best age to discontinue the low phenylalanine diet in phenylketonuria. Clin. Pediatrics 11, 3, 148–156 (1972)
Kang, S., et al.: Results of treatment and termination of the diet in phenylketonuria. Pediatrics 46, 6, 881–890 (1970)
Moncrieff, A.: When to stop the diet in phenylketonuria. Develop. Med. Child Neurol. 6, 1, 59–60 (1964)
Paine, R. A.: Phenylketonuria. Clin. Proc.-Child. Hosp. (Wash.) 20, 6, 143–152 (1964)
Salomons, G., et al.: Evaluation of the affects of terminating the diet in phenylketonuria. J. Ped. 69, 4, 596–602 (1966)
Vandeman, R. P.: Termination of dietary treatment for phenylketonuria. Am. J. Dis. Child. 106, 5, 492–495 (1963)
Author information
Authors and Affiliations
Additional information
Supported in part by United State Department of Health Education and Welfare, S.R.S., International Research Program (Grant No. 05-478-2)
Rights and permissions
About this article
Cite this article
Cabalska, B., Duczyńska, N., Borzymowska, J. et al. Termination of dietary treatment in phenylketonuria. Eur J Pediatr 126, 253–262 (1977). https://doi.org/10.1007/BF00477051
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00477051