Tyrosinemia

Tyrosinemia is a rare genetic metabolic disorder characterized by the inability to break down the amino acid tyrosine due to a deficiency of the enzyme fumarylacetoacetate hydrolase (FAH). In families where both parents are carriers of the gene for the disease, there is a one in four risk that a child will have tyrosinemia.

your quick guide to this page

what is tyrosinemia?: Learn what defines tyrosinemia and what its general consequences are.
fast facts: Get a quick overview of tyrosinemia through statistics and bite-sized facts.
symptoms: Learn about the symptoms of tyrosinemia, how to recognize them, and what to do if you experience them.
lifestyle impacts: Find out how tyrosinemia impacts your lifestyle.
what can I do?: Discover management and treatment strategies for tyrosinemia.
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what is tyrosinemia?

Tyrosinemia is a rare genetic metabolic disorder characterized by the inability to break down the amino acid tyrosine due to a deficiency of the enzyme fumarylacetoacetate hydrolase (FAH). This leads to the accumulation of tyrosine and its toxic byproducts in the liver, kidneys, and central nervous system. The liver is especially affected, resulting in severe liver disease, cirrhosis, and liver cancer if left untreated. In families where both parents are carriers of the gene for the disease, there is a one in four risk that a child will have tyrosinemia.

symptoms

In the acute form of the disease, abnormalities appear in the first month of life. Babies may show poor weight gain, an enlarged liver and spleen, a distended abdomen, swelling of the legs, and an increased tendency to bleeding, particularly nose bleeds. Some children have a chronic form of tyrosinemia with a gradual onset symptoms. In these children, enlargement of the liver and spleen are prominent, the abdomen is distended with fluid, weight gain may be poor, and vomiting and diarrhea occur frequently.

Early symptoms can also include:

Failure to gain weight and grow (failure to thrive)
Fever, diarrhea, vomiting
Enlarged liver (hepatomegaly)
Jaundice (yellowing of skin and eyes)
Cabbage-like odor
Increased tendency to bleed, particularly nosebleeds

impacts on the body

Without proper treatment, it can lead to:

Liver enlargement (hepatomegaly)
Cirrhosis
Increased risk of liver cancer (hepatocellular carcinoma)
Impaired blood clotting due to reduced production of clotting factors
Kidney dysfunction
Changes in mental state
Reduced sensation in limbs (peripheral neuropathy)
Abdominal pain
Breathing problems

lifestyle impacts

Those with tyrosinemia can experience lifestyle impacts such as dietary restrictions (low in tyrosine, phenylalanine, and methionine), regular medical check-ups and monitoring, potential need for liver transplantation in severe cases, and possible developmental delays and learning difficulties.

what can I do?

prevention

Tyrosinemia is a genetic disease and cannot be prevented. However, with early diagnosis and proper treatment, many severe effects of tyrosinemia can be prevented or minimized.

diagnosis

Tyrosinemia is diagnosed through a combination of showing of symptoms, biochemical tests, and genetic analysis. The key methods used for diagnosis include:

Biochemical testing
Blood tests
Urine tests
Newborn screening
Liver function tests
Genetic testing
Prenatal diagnosis

management

With appropriate management, many individuals with tyrosinemia can now live into adulthood with improved quality of life and reduced risk of complications. However, it’s essential to be committed to your treatment plan and maintain regular communication with your healthcare team to manage the condition effectively.

treatment

Medication: Nitisinone (NTBC) to block the production of toxic metabolites
Dietary management: A low-protein diet, specifically restricting tyrosine and phenylalanine intake
Possible liver transplantation: In severe cases or if late diagnosis