Amino Acid Disorders

Print Version
Disease Name Tyrosinemia, type 1
Alternate name(s) Hereditary infantile tyrosinemia, Hepatorenal tyrosinemia, Fumarylacetoacetase deficiency, Fumarylacetoacetate hydrolase
Acronym FAH deficiency
Disease Classification Amino Acid Disorder
Variants Yes
Variant name

Tyrosinemia I chronic-type, Tyrosinemia II, Tyrosinemia III

Symptom onset Infancy
Symptoms Hepatocellular degeneration leading to acute hepatic failure or chronic cirrhosis and hepatocellular carcinoma, renal Fanconi syndrome, peripheral neuropathy, seizures and possible cardiomyopathy.
Natural history without treatment Chronic liver disease leading to cirrhosis and hepatocellular carcinoma. Renal tubular disease (Fanconi syndrome) with phosphaturia, aminoaciduria and often glycosuria. May lead to clinical rickets. Peripheral neuropathy. Self-injurious behavior, seizures and cardiomyopathy have been observed. Coagulation problems.
Natural history with treatment Hepatitic disease may progress despite dietary treatment. NTBC treatment leads to improvements in kidney, liver and neurologic function, but may not affect incidence of liver cancer.
Treatment Dietary restriction of phenylalanine and tyrosine. NTBC (2-(2-nitro-4-trifluoro-methylbenzoyl)-1,3-cyclohexanedione) treatment which improves hepatic and renal function. Liver transplantation when indicated to prevent hepatocellular carcinoma. Vitamin D to heal rickets.
Other Unpleasant odor due to accumulation of methionine. Sometimes described as “cabbage-like” odor.
Physical phenotype No abnormalities present at birth. May develop widely-spaced incisors, pes planus, epicanthus and microcephaly.
Inheritance Autosomal recessive
General population incidence 1:100,000
Ethnic differences Yes
Population French Canadian (Saquency-Lac Saint Jean region) 1:20 carrier rate
Ethnic incidence 1:1846
Enzyme location Liver, kidney, lymphocytes, fibroblasts
Enzyme Function Metabolizes fumarylacetoacetic acid into fumaric acid and acetoacetic acid
Missing Enzyme Fumarylacetoacetate hydrolase
Metabolite changes Increased urinary succinylacetone, increased tyrosine and methionine in serum, increased alpha fetoprotein.
Gene FAH
Gene location 15q23-25
DNA testing available Yes
DNA testing detail DNA for isolated populations
Prenatal testing Enzymatic assay of amniocytes or CVS cells. Direct DNA testing in amniocytes or CVS cells if mutations known. Succinylacetone in amniotic fluid.
MS/MS Profile N/A
Genetests Link
Support Group

National Urea Cycle Disorders Foundation

National Coalition for PKU and Allied Disorders

Children Living with Inherited Metabolic Diseases

  Print Version


THIS INFORMATION DOES NOT PROVIDE MEDICAL ADVICE. All content ("Content"), including text, graphics, images and information are for general informational purposes only. You are encouraged to confer with your doctor or other health care professional with regard to information contained on this information sheet. After reading this information sheet, you are encouraged to review the information carefully with your doctor or other healthcare provider. The Content is not intended to be a substitute for professional medical advice, diagnosis or treatment. NEVER DISREGARD PROFESSIONAL MEDICAL ADVICE, OR DELAY IN SEEKING IT, BECAUSE OF SOMETHING YOU HAVE READ ON THIS INFORMATION SHEET. This project is supported by a grant from the Maternal and Child Health Bureau, Health Resources and Service Administration, Genetic Services Branch, MCH Project #:1H46 MC 00189-03