Genotype F prevails in HBV infected patients of Hispanic origin in Central America and may carry the precore stop mutant

Abstract

The distribution of HBV genotypes and the presence of the precore stop mutation were investigated in HBV strains from Central America. 333 HBsAg positive sera from chronic HBsAg carriers and acute hepatitis B cases from five different countries (Costa Rica, Nicaragua, Honduras, EI Salvador and Guatemala) were tested for HBV DNA by nested PCR. Genotyping by limited sequencing within the S gene was performed on 90 strains, 66 from sera with a high level of HBV DNA, and another 24 from sera positive for HBV DNA only after nested PCR. 23 of the samples were anti-HBe positive. Genotype F was found in 71 (79%), A in 13 (14%), D in 5 (6%) and C in one of the 90 sera. 18 patients with genotype F infection had anti-HBe and HBV DNA in serum. Since the three published precore sequences of genotype F strains have a C1858, which is known to prevent the precore stop mutation from G to A at position 1896, the precore and part of the core genes were sequenced from 19 anti-HBe positive sera with HBV DNA, 17 with genotype F and 2 with genotype A. The A1896 mutation was found in 11 of the 17 genotype F strains. All these had a T1858, which was also present in 5 of the 6 genotype F strains with G1896. The precore region was therefore sequenced from genotype F strains from 5 HBeAg positive sera from the five different Central American countries. These also had a T1858, which thus is the wild type substitution in genotype F in Central America. A number of mutations were recorded between residues 57 and 68 in the core protein corresponding to a unique clustering region of the genotype F strains. The predominance of genotype F in Central American populations of Hispanic origin was not anticipated since this genotype is regarded as indigenous to the Amerindian populations of the New World.

Hepatitis B Virus Genotype D Prevails in Patients with Persistently Elevated or Normal ALT Levels in Turkey

“…Genotype A is the predominant genotype in northern Europe; genotype D is found worldwide, but prevails in the Mediterranean area, the Near and Middle East and south Asia; genotypes B and C are predominant in east Asia and the Far East; genotype E is prevalent in western subSaharan areas; and genotype F is likely to be present in populations with origins on the American continent [5,[22][23][24][25]. Thus, the heterogenity in disease manifestations and response to antiviral treatment among patients with chronic hepatitis B in different parts of the world may, at least in part, be attributed to differences in HBV genotypes.…”

Genetic variability of the S gene of hepatitis B virus: clinical and diagnostic impact

“…The genotypes of HBV have distinct geographical distributions (Table 1). Genotypes A and D have global distributions, genotypes B and C are predominantly in East and South East Asia, genotype E is predominant in West Africa, and the most divergent genotype HBV/F is found exclusively amongst indigenous peoples in Central and South America (Norder et al, 1994;Arauz-Ruiz et al, 1997;Sanchez et al, 2002;Mulders et al, 2004). The geographical location HBV H is restricted to Central and South America (Bartholomeusz and Schaefer, 2004).…”

Hepatitis B virus genotypes and precore/core-promoter mutations in Tunisian patients with chronic hepatitis B virus infection

“…Genotype G has been confined to France and the United States and genotype H has only been found in populations from Central and South America. 6e8, 18,20 During the natural course of chronic HBV infection HBe antigen (HBeAg) is considered as a marker for viral replication; seroconversion from HBeAg to its antibody (anti-HBe) is usually accompanied by cessation of HBV replication and often coincides with clinical remission of liver disease. 9 However, some HBeAg-negative patients remain persistently viremic and continue to have active liver disease.…”