GENOTYPING OF HEPATITIS-B VIRUS BY RESTRICTION PATTERN-ANALYSIS OF A PRE-S AMPLICON

A method is described for genotyping of hepatitis B virus (HBV), based on the restriction fragment length polymorphism (RFLP) created by Ava 2 and Dpn2 action on an amplified segment of the pre-S region. Analysi ng 51 database sequences by phylogenetic tree construction and RFLP pr ediction, the method was shown to be capable of detecting all known ge notypes (A-F). The method was applied to 99 serum samples from hepatit is B e antigen (HBeAg)-positive chronic carriers: comparing observed a garose gel patterns with the RFLP predicted from the database sequence s. In 95 typable samples the following genotypes were observed; 23 A. 20 B, 20 C, 22 D, 5 E and 5 F. Phylogenetic grouping of the 51 databas e sequences and RFLP genotyping of the 99 patient samples were compare d with typing based on S gene analysis, showing disagreement in only o ne case, a database sequence of ayw subtype which was classified as ge notype D by pre-S region and genotype A by S region analysis. This met hod should be useful for epidemiological investigations and for studyi ng the potential influence of genotype on the course of infection. (C) 1998 Elsevier Science B.V. All rights reserved.