[Screening for aminoacidopathies in newborns by means of an aminoacid analyzer. Reference values and statistical determinations (author's transl)].

Plasmatic concentrations of amino acids valine, methionine, isoleucine, leucine, tyrosine and phenylalanine, in 4100 newborns of age varying between 1 and 18 days have been analyzed. The samples were randomly taken among the newborns of Lazio, Abruzzi and Molise subjected to neonatal screening for aminoacidopathies at the Centro delle Oligofrenie Dismetaboliche, Istituto di Neuropsichiatria Infantile. Average concentrations in mumoles/100 ml of the aminoacids and their correlations with weight and age have been studied. A comparison of the results of this research with the already published data is made, and the cut off points in mass screening for aminoacidopathies are calculated.