EARLY DIAGNOSIS OF TYROSINEMIA TYPE I IN THREE INFANTS

K.Utermann. J.Crone. W.D.Huber, D.Möslinger, S.Stockler-Ipsiroglu

Children's Hospital, University of Vienna, Austria

INTRODUCTION: Tyrosinemia type I is an autosomal recessively inherited metabolic disorder caused by the deficiency of the enzyme fumarylacetoacetate hydrolase resulting in the accumulation of tyrosine and its toxic degredation products, succinylacetone mainly. Liver failure can be prevented by early treatment with NTBC which blocks the tyrosine degradation and prevents the accumulation of toxic metabolites. We report clinical recognition patterns in 3 infants with tyrosinemia type I.

CASE REPORTS: In 2 patients hepatomegaly, ascites / impaired liver function with prominent coagulopathy, hypalbuminemia and moderatly increased transaminases combined with phosphate renal loss and hypophoshpatemic rickets were characteristic findings. In patient 3, the diagnostic hint was given by elevated phenylalanine-and galactose levels in routine neonatal screening. All patients showed anemia, thrombocytopenia and high serum alpha-fetoprotein. Diagnosis was confirmed by demonstration of succinylacetone in urine and elevated plasma tyrosine levels.

Treatment with NTBC and low tyrosine and phenylalanine diet resulted in significant clinical and biochemical improvement. Despite early treatment at age 28 days. patient 3 showed the most delayed response with additional development of regeneration nodes in the the liver.

CONCLUSION: Tyrosinemia type I can be recognized within in the first weeks of life by clinical and laboratory signs of liver dysfunction combined with renal hypo-phosphatemia. Tyrosinemia should also be considered in cases with elevated phenylalanine and galactose levels in routine neonatal screening. Early recognition and treatment may prevent major late sequelae.