Table 1.
Main amino acid variants described in the hepatitis B virus genome and its effect
| ORF | Amino acid variant | Effect |
| P | A181T and M204 I/V (compensatory: L80I/V, T128N , R153Q, V173L L180M, A200V1, V207I1) | LMV resistance |
| N236T (compensatory: A181 T/V/S. Low sensitivity: V84M, S85A, L217R, I233V) | ADV resistance | |
| I169T, T184S, S202C/I/G, M250I | ETV resistance2 | |
| A194T1 | TDF resistance | |
| S | G145R W156Stop, W163Stop, W172Stop, W196Stop | Immune therapy failure |
| D144A, P142S, K141E, Q129H, I/T126N, T131I, M133L | HBsAg structural alterations | |
| X | I130M, V131I, F132Y | Contribution to HCC development |
| C | ||
| preCore | A1762T and G1764A | HBeAg negative forms |
| Core | G1896A and G1899A | Disease progression |
| P5H/L/T, D32N/H, C/E43K, cP50A/H/Y, E83D, I97F/L, L100I, A131G/N/P, S181H/P and C/Q182K/stop | HCC development | |
| Regions 50-69 and 74-84 | Immune scape variants |
1
Antiviral treatment resistances not completely defined[58];
2
Linked to lamivudine (LMV) signature (L180M + M204V). ORF: Open reading frames; ADV: Adefovir; ETV: Entecavir; TDF: Tenofovir; HBsAg: Hepatitis B virus (HBV) surface antigen; HBeAg: HBV e antigen; HCC: Hepatocellular carcinoma.