ANOMALOUS PHENYLALANINE LOADING RESPONSES IN RELATION TO CLEFT LIP AND CLEFT PALATE

Abstract

Oral phenylalanine loads were given to 15 mothers of children with cleft lip and palate defects and 19 control women. Four of the 15 mothers exhibited unusual tolerance curves, i.e., the phenylalanine levels did not rise appreciably during four hours nor did the tyrosine levels increase normally. Two of the women studied also showed a deviation from normal in the appearance of tyrosine in the blood after a tyrosine load. Attempts to stress the mothers who exhibited a normal response to the single phenylalanine load by giving them a double load were not successful. The possible implications of these findings are discussed.