Biomedical subjects
Publications and source records attributed to J De Mari.
Screening for tyrosinemia is not routinely performed worldwide. Using a low expense thin-layer chromatography (TLC) for amino acids we detected a high frequency of transient tyrosinemia with secondary hyperphenylalaninemia in some newborns. Serum follow up showed the need to introduce adequate therapy in these babies.
We present the experience and figures about a screening program in South Brazil carried on in Porto Alegre, capital of the Southern Brazilian State. We present the tests performed routinely in our laboratory, the prevalence of some diseases and tests for infectious diseases to be added in the most comprehensive regional program in our country.
OBJECTIVE: To evaluate the frequency of transient neonatal tyrosinemia, with or without secondary hyperphenylalaninemia,observed through neonatal screening for metabolic disorders, andthe need of monitoration and intervention with drugs and/or specialdiet in selected cases. METHODS: 457.870 dried blood samples obtained by heel stickfrom 3 to 20 days old babies were qualitatively evaluated by aminoacid thin-layer chromatography. Positive cases were quantitativelyconfirmed in serum samples by fluorimetric measurement of tyrosineand phenylalanine. RESULTS: 1.231 dried blood samples displayed positive resultsfor tyrosine in the cromatographic evaluation. The fluorimetricserum analysis disclosed normal levels of tyrosine and phenylalaninein 822 patients. The remained 409 patients showed hightyrosine levels and were placed in three groups according to thetyrosine concentration. In 118 of these cases serum phenylalaninewas also increased. CONCLUCIONS: Transient neonatal tyrosinemia is a very frequentdisorder in neonates (1/372); in some cases very high levels werefound, not only of tyrosine but also phenylalanine. As this findingis not yet accepted as absolutely harmless, the monitoration of thissituation and the use of measures to lower the tyrosine and phenylalaninelevels should be considered by the pediatrician.