A Case Report of Hereditary Tyrosinemia type I

Summary of case history: Patient is a 3-year-old female and was first diagnosed on September 1st, 2020 (postnatal day 20) due to lasting high tyrosine level detected for 11 consecutive days. Symptoms and signs: Patient did not exhibit jaundice, hemorrhage, or ascites. Physical examinations did not show any obvious abnormality. Diagnostic methods: Neonatal hereditary and metabolic disease screening was performed and found high tyrosine level, surmising tyrosinemia. Further urine organic acid analyses showed increased levels of succinylacetone (SA), 4-Hydroxyphenylacetic acid, 4-hydroxyphenyllactic acid, and 4-Hydroxyphenylpyruvic acid. Additional blood tests found high levels of alpha-fetoprotein (AFP), serum ammonia, serum lactate, alkaline phosphatase (ALP), and bile acid, reduced hemoglobin and serum phosphorus, and normal levels of alanine transaminase (ALT), glucose, and creatine. Genetic testing found a pathogenic FAH c.553+1G>A homozygous variant in the proband. Parents of the proband carried the same heterozygous variant at this locus. Thus, the patient was diagnosed as hereditary tyrosinemia type I (HT-1). Therapeutic methods: Low tyrosine and phenylalanine diet was given. Phosphate mixture and ursodeoxycholic acid (UDCA) were administered to supplement phosphorus and enhance cholagogue, respectively. Additional therapies aimed to correct anemia and replenish calcium. However, patient’s condition was not well controlled. Clinical outcomes: Anemia and hypophosphatemia shown in the patient were not improved. Under monitoring, high levels of AFP still lasted. Physical examination did not show unusual observations. Parents of the patient were referred and advised to consult about liver transplantation at higher level hospitals.