Type III tyrosinemia
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:
Overview
Overview
Type III tyrosinemia is a rare disorder caused by a deficiency of the enzyme 4-hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27), encoded by the gene HPD. This enzyme is abundant in the liver, and smaller amounts are found in the kidneys. It is one of a series of enzymes needed to break down tyrosine. Specifically, 4-hydroxyphenylpyruvate dioxygenase converts a tyrosine byproduct called 4-hydroxyphenylpyruvate to homogentisic acid. Characteristic features of type III tyrosinemia include mild mental retardation, seizures, and periodic loss of balance and coordination (intermittent ataxia). Type III tyrosinemia is very rare; only a few cases have been reported.
Historical Perspective
Historical Perspective
Classification
Classification
Pathophysiology
Pathophysiology
Causes
Causes
Differentiating Type III tyrosinemia from Other Diseases
Differentiating Type III tyrosinemia from Other Diseases
Epidemiology and Demographics
Epidemiology and Demographics
Risk Factors
Risk Factors
Screening
Screening
Natural History, Complications, and Prognosis
Natural History, Complications, and Prognosis
Natural History
Complications
Prognosis
Diagnosis
Diagnosis
Diagnostic Criteria
History and Symptoms
Physical Examination
Laboratory Findings
Imaging Findings
Other Diagnostic Studies
Treatment
Treatment
Medical Therapy
Surgery
Prevention
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