Abstract
A number of inborn errors of metabolism (IEM) are not yet prenatally detectable. Perhaps most prominent among these is phenylketonuria. It is possible that in the presence of an IEM, the affected fetus will accumulate increased quantities of one or more of the metabolites and that such increases will be detectable by careful analyses of blood. In order to make such determinations, however, adequate methods and normal values must be available. We have quantitatively examined the serum free amino acids in seven fetuses of 12-20 weeks gestation. In most of the examinations 0.1 ml. serum was used although as little as 0.05 ml. was adequate. The serum was diluted and deproteinized in 1.0 ml. 3% sulfosalicylic acid, centrifuged, and the entire supernatant applied to an amino acid analyzer column. Qualitatively, amino acids were the same as those in postnatal blood or amniotic fluid. Amino acid concentrations were generally 2-3 times greater than corresponding concentrations as previously determined in amniotic fluid or maternal plasma of the same gestational time and of newborn plasma obtained on the first day of life. Specific values in u moles/ml, include Phe (.174 ± .049), Lys (.569 ± .138) and Ala (.580 ± .150), the latter two particularly concentrated. Within the gestational range examined, there were no consistent differences in the amino acid concentrations.
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Levy, H., Milunsky, A. & Frigoletto, F. FREE AMINO ACID CONCENTRATIONS IN FETAL SERUM. Pediatr Res 8, 391 (1974). https://doi.org/10.1203/00006450-197404000-00306
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DOI: https://doi.org/10.1203/00006450-197404000-00306