Among the 578 anti-HAV-IgM (+) individuals, 509 (88.1%) individuals were HAV-IgM (+) without severe HA, while 69 (11.9%) showed a severe HA hepatitis course: 31 (5.4%) of the severe HAV infections did not develop liver dysfunction, while 38 (6.6%) did develop severe HA hepatitis with liver dysfunction. The gene discussed is CD40LG; the disease is Hepatitis.