Hepatitis B genotypes distribution in South Asia and Middle East

摘要

We read with interest the recently published article by Awan in your journal (Awan et al., 2010). The authors presented the distribution of HBV genotypes from four parts of Pakistan. Hepatitis B virus genotypes show a characteristic geographic distribution with a proposed association with human migration (Jazayeri and Carman, 2009 S.M. Jazayeri and W.F. Carman, Evolution of Hepatitis B Genotype D in the Middle East and South Asia. Hepat. Monthly, 9 1 (2009), pp. 9–11. | View Record in Scopus | | Cited By in Scopus (4)Jazayeri and Carman, 2009). There are some questions regarding the result and conclusion in this that I would like to ask the authors to answer THEM. The reason for the samples which were not type able is not clear. The signature sequences in the surface protein (MHR region) ALLOCATING different HBV genotypes are conserved. In fact, they are variants and not mutations that designating genotypic differences (Carman, 1997). We agree that PCR-induced mutations might conflict the genotyping results, however, they could have been found easily by direct sequencing. Finding E and F genotypes (as a mixture) is unusual in Pakistan population. These unusual genotypes deserve further investigations. The authors should have used another strategy for genotyping of these suspicious and mixed-genotypes samples (like molecular cloning, bi-direction direct sequencing).