Table 4. Signature nucleotide changes in the regulatory regions of Indian HBV/D4 (IndD4) isolates compared with the previously reported residues at the same position in different subgenotypes of D (D1-D9).
| HBV Regulatory region | Nucleotide position | Nucleotide present in HBV/D subgenotypes | |||||||||
| D1 | D2 | D3 | D4 | D5 | D6 | D7 | D8 | D9 | IndD4 [n = 12] | ||
| Enhancer I/X promoter [nt 1074–1234] | 1126 | A | A | A | A | A | A | A | A | A | C |
| S2 Promoter [∼nt 2971–3127] | 3021 | A | A | A | A | A | A | A | A | A | G |
| 3033 | C | C | C | C | C | C | C | C | C | T | |
| NRE [∼nt 1613–1636] | 1633 | A/G | A | A/G | A/G | A | A | A/G | A | A | G |
| 1310 | C | C | C | C | C | C | C | C | C | T | |
| 1321 | A/C | A | A | A | A/G | A | A/G | A | A/C | G | |
| 1368 | G/A | A/G | G/A | G | G/A | A | G | G | G/A/C | C | |
| PRE [∼nt 1151–1684] | 1405 | C | C | C | C | C | C | C | C | C | T |
| 1407 | G | G/T | G | G | G | G | G/T | G | G | A | |
| 1577 | G | G | G | G | G/A | G | G | G | G | A | |
| 1633 | A/G | A | A/G | A/G | A | A | A/G | A | A | G | |
Unique residues of IndD4 are underlined. The major nucleotide substitutions are indicated in bold.