Complete nucleotide sequences and the characteristics of two hepatitis B virus mutants causing serologically negative acute or chronic hepatitis B

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.