Scanning Of Differentially Methylated Genes Associated With Phenotype In CpG Islands DNA Of Whole Genome Between HBV Infected Monozygotic Twin Pairs

Hepatitis B virus (HBV) infection is one of the major infectious diseases with more than 350 million chronic carriers worldwide, which causes a broad spectrum of liver diseases ranging from acute infection, chronic carrier, severe hepatitis, cirrhosis, hepatocellular carcinoma to liver failure. Several factors contribute to the susceptibility and outcome of HBV infection, including host, viral and environmental factors et al. Host factors include race, sex, age, genomic polymorphisms and immune status. Viral factors include genotype, quasispecies complexity, and superinfection of some other virus. Environmental factors involve the habit, living environment and behavior. Host genetic factors play an important role to determine the susceptibility and the outcome of HBV infection.Twin study is an important model for genetic research. Monozygotic twins (MZ twins) share the common genetic background and developmental environment. The high concordance of diseases phenotype is found between twin pairs. Identical twins are used to estimate the effect of genetic background to the phenotype of diseases, such as complex traits, psychology, character and behavior. We found some twin pairs infected with HBV showing discordant outcome, while this difference have little relationship with the effect of viral factors. Recently, study indicated genetic background of most monozygotic twins is not completely identical, putative role of epigenetic drift may be involved. Epigenetic drift is a phenomenon of accumulated epigenetic changes during the life time of individual, including genomic imprinting difference in embryo stage, pre- and postnatal stochastic events and environmental effect during the growth. Epigenetics is comprised of the stable and heritable (or potentially heritable) changes in gene expression that do not entail a change in DNA sequence. Epigenetics research involves DNA methylation and histone modification, disruption of the balance of epigenetic networks correlates with several major biological events, including regulation of gene expression, reproduction and development,...