Published online Jun 21, 2017. doi: 10.3748/wjg.v23.i23.4222
Peer-review started: January 14, 2017
First decision: March 16, 2017
Revised: March 28, 2017
Accepted: May 9, 2017
Article in press: May 9, 2017
Published online: June 21, 2017
Core tip: To date, naturally occurring mutations in hepatitis B virus (HBV) reverse transcriptase region (RT) in genotype C2-infected patients have rarely been introduced in terms of clinical severity. So, this study characterized the AA substitutions at the aforementioned 42 potential NAr mutation positions in HBV RT sequences from a cohort of 131 Korean treatment-naïve CHB patients with genotype C2 infections. Notably, AA substitutions at positions involved in primary (rt184 and rt204) or secondary drug resistance (rt80 and rt180) were detected in 10 patients [1 CH patient and 9 hepatocellular carcinoma (HCC) patients] and 7 patients (1 CH and 6 HCC patients), respectively. The overall mutation frequencies in the HCC patients (3.17%, 96/3024 mutations) were significantly higher than the frequencies in the CH patients (2.09%, 52/2478 mutations), suggesting that naturally occurring NAr mutations in South Korea might contribute to liver disease progression (particularly HCC generation) in chronic patients with genotype C2 infections. In addition, a total of 3 NAr positions, rt80, rt139 and rt204 were found to be significantly related to HCC from treatment naïve Korean patients.