Tyrosinemia type 3. 4-hydroxyphenylpyruvate dioxigenase deficiency.
Incidence
Rare. Autosomal recessive condition. Only a few patients have been documented suffering from Tyrosinemia type 3.
Clinical Characteristics
Episodes of ataxia (acute intermittent) and drowsiness has been reported in one patient and severe convulsions and cerebral atrophy in another. There is mild mental retardation. It is an autosomal recessive condition. There is no liver dysfunction. The disease is caused by a deficiency of 4-hydroxyphenylpyruvate dioxygenase in liver. Blood tyrosine is highly elevated. In urine, the excretion of 4-hydroxyphenyllactate, 4-hydroxyphenylpyruvate and 4-hydroxyphenylacetate is increased. Treatment consists of tyrosine restriction. The ataxia is reported in infancy. Seizures are present at birth.
Precipitants
Probable high protein ingestion.
Provocation Tests
no
Diagnostic Procedures
EB-L. Blood tyrosine is highly elevated. In urine, the excretion of 4-hydroxyphenyllactate, 4-hydroxyphenylpyruvate and 4-hydroxyphenylacetate is increased.