1. Treatment Variables and Intellectual Outcome in Children With Classic Phenylketonuria
- Author
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Agustin Legido, Donald Carter, Ann Schoemaker, Warren D. Grover, Angelo M. Di George, and Linda Tonyes
- Subjects
Male ,Pediatrics ,medicine.medical_specialty ,Time Factors ,Adolescent ,Intelligence ,Dietary control ,Phenylalanine ,Single Center ,03 medical and health sciences ,0302 clinical medicine ,Phenylketonurias ,030225 pediatrics ,medicine ,Humans ,Child ,Retrospective Studies ,Intelligence quotient ,business.industry ,Age Factors ,Infant ,Classic phenylketonuria ,Mean age ,Prognosis ,Pediatrics, Perinatology and Child Health ,Female ,business - Abstract
Records of 46 patients with classic phenylketonuria (PKU) were used to determine treatment variables associated with intellectual outcome. Patients comprised three groups: phenylalanine-restricted diet started 1) after 3 months and loss of diet control at a mean age of 7 years, 2) before age 3 months and loss of diet control at a mean age of 5 years, and 3) before age 3 months and through a mean age of 11 years. All underwent IQ testing during the diet; groups 1 and 2 were retested at a mean of six years off the diet. On the diet, groups 2 and 3 had higher IQs than group 1; group 3 IQ was also higher than IQ off diet in groups 1 and 2. After discontinuing the diet, group 2 IQs decreased significantly. Predictors of IQ in group 1 were age at loss of diet control and percentage of phenylalanine concentrations >15 mg/dL; in group 2, mean phenylalanine concentrations and age at loss of diet control. Predictors of changes in group 1 IQs were global degree of dietary control and percentage of phenylalanine concentrations >15 mg/dL; in group 2, phenylalanine concentrations of 15 mg/dL achieved no IQ gain by continuing the diet after age 7 years. Thus, intellectual prognosis is best for PKU patients who start a phenylalanine-restricted diet early and continue through age 12 years.
- Published
- 1993
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