Tyrosine transaminase deficiency disease, also known as tyrosinemia type II, is a rare autosomal recessive inherited disorder that affects the metabolism of the amino acid tyrosine. It is caused by a deficiency in the enzyme tyrosine aminotransferase (TAT). This enzyme is responsible for the conversion of tyrosine to p-hydroxyphenylpyruvate in the liver.
Without sufficient TAT activity, tyrosine and its metabolites, such as tyramine and p-hydroxyphenylpyruvate, accumulate in the blood, urine, and tissues of affected individuals, leading to a variety of symptoms and complications. These may include liver dysfunction, hepatomegaly (enlarged liver), renal tubular dysfunction, developmental delay, intellectual disability, and growth failure.
Tyrosine transaminase deficiency disease can present in infancy or early childhood, and symptoms can range from mild to severe depending on the level of enzyme deficiency. Common clinical signs include failure to thrive, jaundice, rickets, and diarrhea. Neurological manifestations can also occur, such as intellectual disability, seizures, and difficulty coordinating movements.
The diagnosis of tyrosine transaminase deficiency disease is typically made through a combination of clinical features, measurement of elevated tyrosine levels in the blood, and confirmation through genetic testing. Treatment primarily involves dietary management, restricting the intake of tyrosine and phenylalanine, which are precursors to toxic metabolites. Supplemental vitamin D and a low-protein diet may also be recommended to mitigate complications.
Early detection and treatment are crucial to prevent long-term complications and improve outcomes for individuals with tyrosine transaminase deficiency disease. Regular biochemical monitoring, dietary management, and close
