Analysis The Variation Of Hepatitis B Virus Genome In Children Failure To HB Vaccine And Their Mothers By High-throughput Sequencing

Objective: To explore the characteristics of HBV mother-to-childtransmission, and the variation of HBV genome in children failure to HBvaccine and their mothers.Methods: Eight children who developed into chronic HBV infectionafter receiving hepatitis B vaccines and their respective mothers wereenrolled into the research, the HBV DNA was extracted from serum, thefull length of HBV gene was amplified by PCR, the HBV gene was madeto small fragments, different barcodes primers were attached to fragmentsby PCR, the250bp-500bp fragments were extracted from gel andsequenced by solexa sequencing technology. The sequencing data wereanalysised by statistical methods. Liver function, HBVM and HBV DNAlevel were determined for each patient.Results:(1) The sequencing data utilization of solexa was about39%,the low coverage presented in nt900, nt1800and nt2600of HBV.(2) Thesequences in paired mother and child could cluster well, the sequencehomology between paired mother and child was beyond99%.(3) The HBV genotype in8pairs of mother-child was mixtures of B and C,6pairs ofthem were dominant B, and2pairs were C. The HBV genotype wasidentical between paired mother and child.(4) The significantpolymorphism positions existed in whole HBV gene among the children,and nt200-300and nt700-800in S, the Pre C, nt1950-2100in C and nt2650-2850in P genes were the hotter sites.(5) Significant polymorphismpositions could be found in every immunized child. There were10significant polymorphism positions in “a” determinant region among8pairs. aa143only existed in children and aa124only existed in mother. TheI126T and G145R in HBsAg “a” determinant region were demonstrated intwo children.Conclusions: High-throughput sequencing technology can detectlowlevel variants in HBV, the HBV in children are delivered from theirmothers, may be the most important reason for vaccine failure. Thedominant HBV genotype in Chongqing is B, the significant polymorphismpositions present in whole HBV gene of the children, most of them in “a”determinant region are transferred from their mothers.