All issues > Volume 43(9); 2000

Original Article

J Korean Pediatr Soc. 2000;43(9):1232-1240. Published online September 15, 2000.

Hepatitis B Virus Pre-S Gene Mutations in Children with Chronic Hepatitis B Infection

Jae Young JY Kim², Woo Yeong WY Chung¹, Chul Ho CH Kim¹

¹Department of Pediatrics, College of Medicine, Inje University, Pusan Paik Hospital, Pusan. Korea
²Department of Pediatrics, St. Benedict Hospital, Pusan, Korea

Correspondence Woo Yeong WY Chung ,Email: chungwy@chollian.net

Abstract

Purpose
: The envelope of HBV consists of three polypeptides which are encoded in pre-S/S open reading frame. Three translation initiation sites are present within this pre-S/S open reading frame, i.e. pre-S1, pre-S2, and S, allowing the expression of large, middle and small HBs proteins. The pre-S1 is thought to carry the receptor binding site for viral entry into hepatocyte but definite proof for this unique function has not been established. The pre-S2 region has been found to contain the binding site for polymerized human serum albumin, which is believed to be involved in the attachment of HBV to human hepatocyte membrane. The aims of this study were to investigate the frequency and role of HBV pre-S mutations in children with chronic hepatitis B infection.
Methods
: Sera from 17 children with chronic hepatitis B infection were analyzed by direct sequencing of polymerase chain reaction amplification of HBV DNA. PCR products were cloned out using T vector system, followed by direct sequencing.
Results
: Seventeen adr types were analyzed. The deletions in HBV pre-S region were observed in 6(35.3%) of 17 cases. Of 6 deleted cases, 3 had an in-phase deletion in the pre-S1 region spanning 18 bp, 132 bp, 183 bp, and 2 had an in-phase deletion in the pre-S2 region spanning 39 bp. Another case had a 447 bp deletion both in the pre-S1 and pre-S2 region as continuous pattern. Various point mutations in HBV pre-S region were detected in 16(94.1%) of 17 cases, and these mutations were observed more frequently in the pre-S1 region than pre-S2 region.
Conclusion
: These observations suggest that deletion and point mutations in HBV pre-S1 and pre-S2 regions were frequently detected in children with chronic hepatitis B infection.

Keywords :Hepatitis B virus, Deletion, Point mutation, Pre-S1 and pre-S2 region, Children