The outcome of seven patients with hereditary tyrosinemia type 1

Hereditary tyrosinemia type 1 (HT1) is a rare, inborn error of tyrosine metabolism. It is a fatal disorder without treatment. Early treatment may prevent acute liver failure, renal dysfunction, liver cirrhosis, hepatocellular carcinoma (HCC) and improves survival. The aim of the present study is to describe the clinical, biochemical, imaging and follow-up of seven patients with HT1 and to define the consequences of the late and interrupted treatment.

A retrospective study was carried out with seven HT1 patients.

The median age at onset of clinical symptoms was 11.2 months (range, 3-28 months) and the median age at diagnosis was 22 months (range, 6-58 months). Liver enzymes and coagulation parameters were back to normal in all symptomatic patients in about 2 weeks. Alfa-fetoprotein (AFP) levels were normalized within the first year of therapy. Hypoechoic nodule formation was detected in two of the seven patients despite drug treatment without an increase of AFP and any dysplastic changes in the biopsies. One patient died due to metastatic HCC because of the late diagnosis and the poor compliance of the follow-up.

This study showed once again that adherence to the treatment and a follow-up schedule of the patients are very important. Also it should not be forgotten that nodule formation can occur despite nitisinone treatment without an increase of AFP. Despite nitisinone treatment, HT1 patients still carry the risk of HCC. HCC must be detected before metastasis to other organs otherwise, patients may lose the chance for liver transplantation.