Tyrosinemia type III is an autosomal recessive disorder caused by the deficiency of 4- hydroxyphenylpyruvate dioxygenase (4-HPPD). It is characterized by elevated levels of blood tyrosine and massive excretion of its derivatives into the urine. Clinical findings of tyrosinemia type III include neurological symptoms and mental retardation. Only a few patients presenting with this disease have been described, and the clinical phenotype remains variable and unclear. We present a case, who was admitted to the hospital at the age of 4 months for recurrent seizures. Two months later, she was admitted again with status epilepticus. Laboratory data showed increased level of tyrosine in the blood. She was treated with a diet low in tyrosine and phenylalanine and anamix formula that leading to catch-up growth and improvement of her symptoms. Plasma tyrosine level dropped to normal values. In any child who presents with the neurologic symptom, some rare diagnosis like tyrosinemia type III should be considered.
Keywords: Mental retardation; status epilepticus; tyrosinemia type III.