Hereditary Tyrosinemia Type-1 With Late Presentation: A Case Report.

The etiology of hereditary tyrosinemia type 1 (HT-1) is the absence of fumarylacetoacetate hydrolase (FAH), an enzyme that catalyzes the last stage of the tyrosine breakdown process. With an autosomal recessive inheritance pattern, it is an uncommon genetic condition. We present a case of HT-1 in a three-year-old female child characterized by abdominal distension, facial edema, lower limb edema, and an enlarged liver with parenchymal disease. A liver biopsy confirmed mixed nodular cirrhosis, and a subsequent whole exome sequencing revealed autosomal recessive inheritance of tyrosinemia type 1. The patient is currently undergoing treatment with capsule nitisinone 5 mg, which inhibits the second step of tyrosine degradation to prevent tyrosinemia, along with a restricted protein diet, while awaiting liver transplantation.