Aetiology
Tyrosinaemia type 1 is a rare, inherited disorder caused by a mutation in the gene responsible for the production of the enzyme fumarylacetoacetate hydrolase (FAAH). This enzyme is essential for the metabolism of the amino acid tyrosine.
Diagnosis
Diagnosis of tyrosinaemia type 1 is made based on a combination of physical findings, laboratory tests, and genetic testing. Physical findings may include jaundice, hepatomegaly, splenomegaly, ascites, and poor weight gain. Laboratory tests may include elevated levels of tyrosine and other amino acids in the blood, decreased levels of FAAH activity in the blood, and elevated levels of succinylacetone in the urine. Genetic testing may be used to confirm the diagnosis.
Differential diagnosis
The differential diagnosis for tyrosinaemia type 1 includes other inherited disorders of tyrosine metabolism, such as tyrosinemia type 2 and 3, and other metabolic diseases, such as phenylketonuria and galactosemia.
Treatment
Treatment for tyrosinaemia type 1 includes a low-protein diet, supplementation with tyrosine and other amino acids, and medication to reduce tyrosine concentrations in the blood.
Prognosis
The prognosis for tyrosinaemia type 1 depends on the severity of the disorder and the age at which it is diagnosed. Early diagnosis and treatment can help prevent long-term complications and improve the prognosis.