Viral Hepatitis
Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Oct 7, 2008; 14(37): 5674-5682
Published online Oct 7, 2008. doi: 10.3748/wjg.14.5674
Virologic characteristics of hepatitis B virus in patients infected via maternal-fetal transmission
Tao Shen, Xin-Min Yan, Yun-Lian Zou, Jian-Mei Gao, Hong Dong
Tao Shen, Xin-Min Yan, Yun-Lian Zou, Jian-Mei Gao, Hong Dong, The Institute of Basic Medicine of the First People’s Hospital of Yunnan Province, Kunming 650032, Yunnan Province, China
Tao Shen, Xin-Min Yan, Yun-Lian Zou, Jian-Mei Gao, Hong Dong, The Institute of Basic Medicine of the First People’s
Author contributions: Shen T and Yan XM designed research; Shen T, Zou YL, Gao JM and Dong H performed research; Shen T, Zou YL and Gao JM performed sequencing; Shen T analyzed data and wrote the paper. Yan XM provided advice and review. All authors read and approved the final manuscript.
Supported by The Natural Science Foundation of Yunnan Province, No.200300172; Hospital Science Foundation of The First People’s Hospital of Yunnan Province (2004)
Correspondence to: Xin-Min Yan, Institute of Basic Medicine of the First People’s Hospital of Yunnan Province, 157 Jinbi Road, Kunming 650032, Yunnan Province, China. yxmin08@163.com
Telephone: +86-871-3638453 Fax: +86-871-3648772
Received: July 16, 2008
Revised: August 22, 2008
Accepted: August 29, 2008
Published online: October 7, 2008
Abstract

AIM: To determine whether HBV with the same characteristics causes dissimilar mutations in different hosts.

METHODS: Full-length HBV genome was amplified and linked with pMD T18 vector. Positive clones were selected by double-restriction endonuclease digestion (EcoRI and HindIII) and PCR. Twenty seven clones were randomly selected from an asymptomatic mother [at two time points: 602 (1 d) and 6022 (6 mo)] and her son [602 (S)], and the phylogenetic and mutational analysis was performed using BioEditor, Clustal X and MEGA software. Potential immune epitopes were determined by the Stabilized Matrix Method (SMM), SMM-Align Method and Emini Surface Accessibility Prediction.

RESULTS: All of the 27 sequences were genotype C, the divergence between the mother and son was 0%-0.8%. Compared with another 50 complete sequences of genotype C, the mother and her son each had 13 specific nucleotides that differed from the other genotype C isolates. AA 1-11 deletion in preS1 was the dominant mutation in the mother (14/18). The 1762T/1764A double mutation existed in all clones of the mother, 3 of them were also coupled with G1896A mutation, but none were found in the son. 17 bp deletion starting at nucleotide 2330 was the major mutation (5/9) in the son, which caused seven potential HLA class I epitopes and one B cell epitope deletion, and produced a presumptive new start codon, downstream from the original one of the P gene.

CONCLUSION: The HBV strain in the son came from his mother, and discrepant mutation occurred in the mother and her son during infection.

Keywords: Hepatic B virus; Vertical transmission; Full genome; Mutation; Phylogenetic; Deletion