What Is the Best Blood Sampling Time for Metabolic Control of Phenylalanine and Tyrosine Concentrations in Tyrosinemia Type 1 Patients?

Background: Treatment of hereditary tyrosinemia type 1 with nitisinone and phenylalanine and tyrosine restricted diet has largely improved outcome, but the best blood sampling time for assessment of metabolic control is not known.

Aim: To study diurnal and day-to-day variation of phenylalanine and tyrosine concentrations in tyrosinemia type 1 patients.

Methods: Eighteen tyrosinemia type 1 patients aged >1 year (median age 7.

Infants with Tyrosinemia Type 1: Should phenylalanine be supplemented?

Tyrosinemia type 1 (HT1) is an inborn error of tyrosine catabolism caused by fumarylacetoacetase deficiency. Biochemically, this results in accumulation of toxic metabolites including succinylacetone. Clinically, HT1 is characterized by severe liver, kidney, and neurological problems.