Table 1.
HBV genotypes and their distinguishing features.
| Genotype | Genome Size (bp) |
Subgenotypes | Distinguishing Features |
|---|---|---|---|
| A | 3 221 | A1, A2, A4, and quasi-subgenotype A3 |
6 bp insertion at the 3′-end of core gene (Insertion of aa 153 and 154 in HBcAg) Unusual G1896A mutation Common BCP mutations |
| B | 3 215 | B1, B2, B4–B6, and quasi-subgenotype B3 |
B1 and B5 are pure HBV/B strains B2, B3, and B4 are recombinants with genotype C in the core region |
| C | 3 215 | C1-C16 | Common BCP mutations |
| D | 3 182 | D1-D6 | 33 bp deletion at the 5′-end of pre-S1 region (Deletion of aa 1-11 in pre-S1) |
| E | 3 212 | - | 3 bp deletion at 5′-end of the pre-S1 region (Deletion of aa 11 in pre-S1) |
| F | 3 215 | F1-F4 | Unusual G1896A mutation |
| G | 3 248 | - | 36 bp insertion at position 190 in the core ORF (Insertion of 12 aa in HBcAg) 3 bp deletion at the 5′-end in the pre-S1 region (Deletion of aa 11 in pre-S1) Stop codons at positions 2 and 28 (G1896A) of the pre-core ORF render it unable to express HBeAg Usually found in coinfection with other genotypes that express HBeAg |
| H | 3 215 | - | Unusual G1896A mutation |
| I | 3 210 | I1 and I2 | Evolved as a recombinant of genotypes A, C, and G |
| J | 3 182 | Single HBV isolate identified in an elderly Japanese patient with HCC Highly divergent from others human HBV strains Likely a genotype C–gibbon Orthohepadnavirus recombinant strains |