Results of screening for phenylalanine and other amino acid disturbances among pregnant women.

Blood specimens were collected from 15000 pregnant women during the first 3 months of their pregnancy and screened for amino acid disturbances by means of paper chromatography. A high incidence of disturbances in the phenylalanine metabolism was discovered: three cases of mild hyperphenylalaninaemia without phenylpyruvicaciduria (incidence 1:5000); two cases of mild hyperphenylalaninaemia with phenylpyruvicaciduria (incidence 1:7550); four cases of mild phenylketonuria (incidence 1:3750). Disturbances in the metabolism of other amino acids were found to be rare. Metabolic and genealogical findings in some detected families are briefly described.