Amino Acid Disorders

 

Tyrosinaemia Type 1 & 2 (TYRO)

 

Definition

Tyrosinaemia is an autosomal recessive inherited disorder in which the body cannot effectively break down the amino acid tyrosine. Levels of tyrosine and other harmful metabolites can build up in the blood and cause damage to the body.

Diagnosis

The condition is diagnosed during newborn screening via the heel prick test taken 48-72 hours after birth..

Prevalence

1:100,000 estimated worldwide

Treatment

Tyrosinaemia type I is treated using the administration of nitisinone (NTBC), a protein restricted diet and amino acid supplements free from phenylalanine and tyrosine. Treatment with nitisinone has reduced the need for liver transplantation and combined with a low-protein diet allows most patients to remain in good health.

Tyrosinaemia type II is treated using a low protein diet and amino acid supplements free from phenylalanine and tyrosine.

When tyrosinaemia is detected early and treated, children are able to remain in good health.

Support Links & Materials

Tyrosinaemia Handbook

TYR Fruit and Veg Counting Lists

TYR General Protein Counting Lists