Somitic disruption of GNAS in chick embryos mimics progressive osseous heteroplasia.

OBJECTIVES

The aims of this study were to determine the hepatitis B virus (HBV) genotypes in hepatitis delta virus (HDV) RNA-positive patients and to characterize the HBV nucleotide sequences that may be found on a distant island of Japan.

METHODS

This study included three patients with chronic hepatitis who were positive for hepatitis B surface antigen (enzyme-linked immunosorbent assay; ELISA), HDV antibody (ELISA) and HDV RNA by polymerase chain reaction (PCR). The HBV genotype was determined by nested PCR using type-specific primers. The first-round PCR products from two patients were sequenced, followed by an investigation of nucleotide homology.

RESULTS

Viruses from all three patients in this study were classified as HBV genotype B. Comparison with HBV isolates from geographically neighboring regions revealed that the two HBV isolates had 97.9-98.6% identity at the nucleotide level to a Chinese isolate, 98.3-98.6% identity to the Okinawa isolate and 98.6-98.8% identity to a Japanese isolate of genotype B. On phylogenetic analysis, the HBV isolates from the two patients were classified as HBV genotype B. The HBV isolates of cases 1 and 3 clustered in the same group as isolates from the Chinese mainland and Japanese mainland, which are geographically near Miyako Island.

CONCLUSION

The HBV isolates coinfected with HDV found on Miyako Island were of genotype B. The PCR method based on genotype-specific primers was useful in determining HBV genotypes.