Diagnosis and treatment of tyrosinosis.

Recovery after dietary treatment of an infant with features of tyrosinosis.

“…The analytical and chromatographic methods were those previously described (Fairney et al, 1968). When first examined at the age of 22 weeks, the plasma phenylalanine and tyrosine levels were raised (5 and 8 mg./100 ml., respectively); other plasma amino acids were at the upper limit of normal There was a severe generalized aminoaciduria, and the urinary phenolic acid chromatogram showed a gross excretion of phydroxyphenyllactic acid, and to a lesser extent phydroxyphenylacetic and p-hydroxymandelic acids.…”

“…Steatorrhoea in tyrosinosis has been poorly investigated, and though it is generally assumed to be secondary to hepatic cirrhosis, the possibility of a specific intestinal lesion has not been excluded. Though in some cases the rickets has healed on dietary treatment alone, or with small amounts of additional vitamin D (Halvorsen et al, 1966;Aronsson et al, 1968), large doses of vitamin D may be necessary in addition to dietary treatment (Fairney et al, 1968), and occasionally hypercalcaemia has been induced (Gentz, Jagenburg, aud Zetterstrom, 1965). In our patient hypercalcaemia occurred after only a modest increase in dosage (10,000 units daily for 2 weeks), and this may have been related to coincident improvement in intestinal absorption.…”

“…Treatment with a low-tyrosine low-phenylalanine diet is usually followed by rapid and marked improvement in renal function, and subsequent healing of rickets (Halvorsen et al, 1966;Sass-Kortsak et al, 1967c), but its effectiveness in preventing the development of hepatic cirrhosis has not yet been established. In all cases so far reported attempts to terminate the dietary treatment have been followed by rapid clinical and biochemical relapse, and it has been assumed that long-term treatment is therefore essential (Fairney et al, 1968;Aronsson et al, 1968).…”

“…methionine. After diagnosis was established a diet restricted in tyrosine and phenylalanine (Fairney et al, 1968) was started. Initially tyrosine was reduced to 25 mg./kg.…”

Neonatal Hepatitis in Premature Infants Simulating Hereditary Tyrosinosis

“…Hereditary tyrosinosis is an inherited metabolic disorder characterized by hepatocellular liver damage which may progress to cirrhosis, hypophosphataemic rickets, renal tubular defects, skin pigmentation, and a moderately raised serum tyrosine. When recognized early, the clinical course can be modified by a restriction of phenylalanine and tyrosine in the diet (Sass-Kortsak et al, 1967;Fairney et al, 1968). The case histories of 3 premature infants with neonatal hepatitis are described in whom complications produced a clinical picture like hereditary tyrosinosis.…”