Tyrosinemia Type 1: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Tyrosinemia Type 1?
A metabolic specialist, often called a biochemical geneticist, usually leads care, with a liver specialist called a hepatologist, a dietitian, and sometimes a genetic counselor completing the team. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Tyrosinemia type 1 is a rare inherited disease that affects the body's ability to break down tyrosine, an amino acid that makes up proteins in food. People with this condition lack enough of a working enzyme, so a harmful substance builds up and can damage the liver and kidneys. Early treatment can change a child's life.
Symptoms
Symptoms usually begin in the first few months of life. Babies may fail to gain weight and grow as expected, a problem called failure to thrive. They may vomit, have diarrhea, and smell of boiled cabbage or maple syrup. The liver can become enlarged and scarred, and some children develop jaundice, a yellowing of the skin and eyes. There is also an increased risk of liver cancer later in life.
Causes and who gets it
Tyrosinemia type 1 is caused by changes, called mutations, in a gene known as FAH. A child must inherit one changed copy from each parent, a pattern called autosomal recessive. Parents carrying only one changed copy usually have no symptoms. The condition is rare but more common in certain isolated populations, such as the Saguenay-Lac-Saint-Jean region of Quebec.
How doctors diagnose it
Many cases are found through newborn screening, a blood test done shortly after birth in every US state. Doctors confirm the diagnosis with blood and urine tests, and genetic testing can show the changed FAH gene. Early diagnosis matters because treatment started soon after birth leads to better results.
Treatment
The main treatment is nitisinone, taken daily as a capsule or tablet. It blocks production of the harmful substance that damages the liver and kidneys. Treatment also includes a strict low-protein diet limiting tyrosine and phenylalanine, planned with a dietitian. Severe liver damage may require a transplant.
When to see a doctor
See a doctor if a baby is not gaining weight, vomits often, has diarrhea, or seems weak or unusually fussy. Yellowing of the skin or eyes, a swollen belly, or a cabbage-like or maple syrup-like smell also need prompt attention. Diagnosed children need regular follow-up to check liver health.
How a direct primary care or concierge doctor fits in
A direct primary care or concierge doctor can be the family's main point of contact, coordinating specialist visits, tracking lab results, and answering questions between appointments. Longer visits and easier access help families keep up with lifelong monitoring.
Common questions
Can children with tyrosinemia type 1 live normal lives?
With early diagnosis and treatment with nitisinone and diet, many children do well and have active lives. Results differ, and lifelong monitoring is needed. Children diagnosed late may have more liver damage.
Is tyrosinemia type 1 contagious?
No. It is an inherited genetic condition, so a child is born with it. It cannot spread from person to person.
Can it be found before symptoms appear?
Yes. Newborn screening blood tests in every US state can detect it in the first days of life, allowing treatment to start before damage happens.
Does the diet last forever?
Most people need the low-protein diet for life, even while taking medicine. The dietitian adjusts the plan as a child grows. Stopping it can allow harmful substances to build up again.
Sources
- NIH Genetic and Rare Diseases Information Center - Tyrosinemia type I
- NCBI Bookshelf - Wilson Disease - GeneReviews®
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
