consequently , in every newborn infant with positive guthrie test results , a rapid investigation of bh4 metabolism should be accomplished in order to differentiate between phenylalanine-hydroxylase deficiencies ( phenylketonuria , mild hyperphenylalaninemia , transient hyperphenylalaninemia ) and bh4 deficiencies .
C0048897
bh4
C0031485
phenylketonuria