With the clustering of diseases, public health response and planning depends on establishing a clear working definition, and the WHO has presented a working case definition of confirmed, probable, and epi-linked cases: (1) Confirmed: Not applicable at present; (2) Probable: A person presenting with acute hepatitis (non-HepA–E) with serum transaminase >500 IU/L (AST or ALT), who is 16 years and younger, since 1 October 2021; (3) Epi-linked: A person presenting with acute hepatitis (non-HepA–E) of any age who is a close contact of a probable case, since 1 October 2021. The gene discussed is GPT; the disease is Acute hepatitis.