1 Research Institute, The Hospital for Sick Children, Toronto
The early clinical histories of 36 patients with phenylketonuria were studied. It was found that more than half the patients had suffered from symptoms of one sort or another in the early weeks of life. These symptoms began months before any sign of mental defect was evident to the parents. The main symptoms found were vomiting (17 patients), irritability (12 patients) and infantile eczema (6 patients). Some patients had more than one symptom. Three children had pyloric stenosis.
The findings are discussed. It is suggested that in these patients vomiting and irritability in early life may be due to a "toxic" effect of phenylalanine or its derivatives on the brain. It is recommended that all infants having these symptoms, as well as those with infantile eczema, a peculiar smell, seizures, suspected or actual mental retardation or a retarded (or phenylketonuric) sibling, should be tested for phenylketonuria.