Transient tyrosinemia in a premature infant
Hertel, J.
Ugeskrift for Laeger 142(20): 1286-1287
1980
ISSN/ISBN: 0041-5782 PMID: 7404719 Document Number: 165864
A premature (26 weeks) male infant (835 g) with transient tyrosinaemia is described. Glucose-fructose (invertose) was given by vein 3 h after birth and by mouth at 16 h; from 36 h, parenteral amino acids and carbohydrates were given for 2 days. Vitamin C (40 mg/kg) was given between days 3 and 9 because of high serum tyrosine values and from days 6 to 9 glucose was given by vein with amino acids (but without tyrosine, phenylalanine and methionine). Serum tyrosine values were highest on day 4 (1343 mu mol/litre) and fell to 47 mu mol/litre on day 8; serum phenylalanine values were highest on day 4 (488 mu mol/litre) and fell to 15 mu mol/litre on day 7; serum methionine values were highest on day 4 (169 mu mol/litre), falling to 11 mu mol/litre on day 6. Normal serum values of these amino acids are less than 200, 100 and 50 mu mol/litre, respectively. The urine contained large amounts of p-hydroxyphenyllactate on days 3 to 5, but no succinyl acetone. The rise in plasma tyrosine, phenylalanine and methionine on days 2 to 4 was due to protein catabolism; the fall in serum phenylalanine and methionine after 3 days was much greater than that of tyrosine. The large fall in the tyrosine concentration on days 7 and 8 was explained by the absence of dietary tyrosine and phenylalanine, the delayed effects of vitamin C and perhaps protein synthesis. The infant developed normally. The diet of premature infants should be low in tyrosine.