• mutation;
  • silent infection;
  • hepatitis F;
  • X gene;
  • X protein


Hepatitis B virus (HBV) DNA was amplified by the polymerase chain reaction from the sera of a patient with acute hepatitis and a patient with chronic hepatitis. Both patients were negative for serum hepatitis B surface antigen and hepatitis B core antibodies and had been previously diagnosed as non-A, non-B, non-C, non-D, non-E hepatitis. The nucleotide sequence revealed an 8-nucleotide deletion in the X-gene coding region creating a C-terminally truncated X protein, and probable mutation of the enhancer 11/core promoter element. In addition, DR2 showed a T-to-C mutation at the extreme 5′-terminus. These mutations within the X-gene coding region must suppress replication and expression of HBV DNA, and this seems to be responsible for absence of serological markers despite the presence of HBV infection. © 1995 Wiley-Uss, inc.