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Tyrosinemia, type III

(TIE-ruh-sin-EE-mee-uh • type • 3)

General Condition Information

Other Names

  • Tyrosinemia
  • Tyrosinemia III
  • Tyrosinemia type III

Condition Type

Birth Prevalence

  • It is unknown how many babies are born with this rare condition each year in the United States.

Screening Finding

Increased tyrosine

What is tyrosinemia, type iii

Tyrosinemia type III is an inherited (genetic) condition that prevents the body from processing proteins correctly. Your body breaks down the protein that you eat into parts called amino acids. Your body then uses those amino acids to make other proteins that it needs to function.

There are several enzymes in your body that break down an amino acid called tyrosine. The process of breaking down tyrosine happens in multiple steps. Each step needs a specific enzyme. In tyrosinemia, one of these enzymes is not working well. Either the body does not make enough enzyme, or does not make the enzyme correctly. People with tyrosinemia have trouble with the process of breaking down tyrosine. 

There are different types of tyrosinemia: type I, type II, and type III. The type your baby has depends on which enzyme in the process is not working. 

In tyrosinemia type III, the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD) is not working. As a result, tyrosine and other related substances build up in your baby’s body. This buildup can damage the brain. Without treatment, this damage can lead to the signs and symptoms of the condition. 

Newborn Screening and Follow-Up

Condition Details

Treatment and Management

It is important to talk to your health care provider about which treatment(s) are best for your baby. The goal of treatment is to prevent the health problems caused by this condition. 

Treatments may include the following:

  • Diet low in protein
  • Special foods and formulas for children with tyrosinemia type III

Children who receive early and ongoing treatment for tyrosinemia type III can have healthy growth and development.

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