Tyrosinaemia Type 1: a clinical case report

Abstract

Tyrosinaemia type 1 is an inherited metabolic disorder caused by the deficiency of fumaryl-acetoacetato hydrolase, a terminal enzyme in the degradation pathway of tyrosine. It affects the liver, central nervous system and the kidneys. 

Objective: The rarity of tyrosinaemia type 1 is such that we consider this report important, in order to improve the clinical and laboratory suspicion of this disorder, because with early treatment the prognosis is improved. 

Case report: a boy aged 1 month and 11 days was admitted to the Padre Hurtado hospital with hyperemesis, abdominal distension and fever of unknown origin. On admission he had macroscopic haematuria and a left palpable kidney. A renal ultrasound showed nephrocalcinosis and bilaterally enlarged kidneys. Biochemical screening showed hypercalciuria, hypercalcaemia, hypophosphataemia, hypoalbuminaemia, elevated alkaline phosphatase, LDH, transaminases, bilirubin, an increased tubular reabsorption of phosphate and x-ray signs compatable with rickets. All cultures were negative. The patient continued with abdominal distension and a repeat abdominal ultrasound showed mild ascites. Liver function tests were abnormal, prothrombin time 10%, TTPK 112s. Due to the high suspicion of tyrosinaemia, alphafetoprotein and amino acid screening were performed, the results confirming the diagnosis. 

Conclusion: The review of the related literature shows the full range of clinical presentations, and a new treatment to improve the outcome in these patients.