Hereditary tyrosinemia type I

Tyrosinemia type 1 is an autosomal recessive disorder of metabolic origin. Progressive renal tubular defects and hepatocellular carcinoma are the primary manifestations.

Epidemiology

More common in Turkey, India and Europe.

Clinical presentation

Presentation is typically in the first few months of life with:

• hepatic failure
• hepatocellular carcinoma
• neural crisis
• rickets
• renal dysfunction
• developmental delay

Pathology

Hereditary tyrosinemia type I is caused by a deficiency of fumarylacetoacetate. High serum succinylacetone and tyrosine levels are diagnostic, with serum succinylacetone levels being more reliable.

Treatment and prognosis

Treatment options include the early use of nitisinone, and a diet of low protein, tyrosine and phenylalanine. Early intervention decreases the chance of malignancy, as well as prolonging survival. Liver transplant is reserved for patients with poor response to nitisinone therapy.