1 Child Guidance Clinic, Children's Memorial Hospital, 2300 Children's Plaza, Chicago, Illinois 60614
2 Children's Hospital Medical Center 300 Longwood Avenue Boston, Massachusetts 02115
The recent article by Dr. Kang and her associates1 reviewed their treatment of 82 classical and atypical phenylketonuric children. They arrive at the conclusion that late-treated classical PKU patients function at a significantly lower intellectual level than their non-PKU siblings, while early-treated PKU patients are not different from their own sibling controls. Interestingly, no significant difference was found between the IQ scores of early-treated and late-treated PKU children in their sample. This inconsistency (A > B, B = C, A = C) may have arisen from either, or both, of two reasons.