BackgroundThe global burden of chronic liver disease is rising. Besides environmental, behavioral, viral and metabolic factors, genetic polymorphisms in patatin-like phospholipase-3 (PNPLA3) and vitamin D receptor (VDR) genes have been related to the development of chronic liver disease and progression towards liver cancer. Although their prevalence differs remarkably among ethnic groups, the frequency of these polymorphisms in South American populations -whose genetic background is highly admixed- has been poorly studied. Hence, the aim of this study was to characterize polymorphisms related to chronic liver disease and their association with the genetic ancestry of South American populations.ResultsDNA samples from 258 healthy unrelated male volunteers were analyzed. The frequencies of G and C alleles of rs738409 polymorphism (PNPLA3 gene) were 74 % and 26 %, respectively; whereas the bAt (CCA) haplotype (VDR gene) was observed in 32.5 % of the samples. The GG genotype of PNPLA3 rs738409 and the bAt (CCA) haplotype -associated with an increased risk of chronic liver disease and progression towards liver cancer- were significantly more frequent among samples exhibiting maternal and paternal Native American haplogroups (63.7 % and 64.6 %), intermediate among admixed samples (45.1 % and 44.9 %; p = 0.03) and the lowest for Non-native American ancestry (30.1 % and 29.6 %; p = 0.001 and p = 0.0008).ConclusionsThese results suggest that individuals with Native American ancestry might have a high risk of chronic liver disorders and cancer. Furthermore, these data not only support the molecular evaluation of ancestry in multi-ethnic population studies, but also suggest that the characterization of these variants in South American populations may be useful for establishing public health policies aimed at high risk ethnic communities.Electronic supplementary materialThe online version of this article (doi:10.1186/s12863-015-0255-3) contains supplementary material, which is available to authorized users.

The prevalence of genetic polymorphisms identified as predictors of therapeutic-induced hepatitis C virus (HCV) clearance differs among ethnic groups. However, there is a paucity of information about their prevalence in South American populations, whose genetic background is highly admixed. Hence, single-nucleotide polymorphisms rs12979860, rs1127354 and rs7270101 were characterized in 1350 healthy individuals, and ethnicity was assessed in 259 randomly selected samples. The frequency of rs12979860CC, associated to HCV treatment response, and rs1127354nonCC, related to protection against hemolytic anemia, were significantly higher among individuals with maternal and paternal Non-native American haplogroups (64.5% and 24.2%), intermediate among admixed samples (44.1% and 20.4%) and the lowest for individuals with Native American ancestry (30.4% and 6.5%). This is the first systematic study focused on analyzing HCV predictors of antiviral response and ethnicity in South American populations. The characterization of these variants is critical to evaluate the risk-benefit of antiviral treatment according to the patient ancestry in admixed populations.

The prevalence of HHV-8 infection varies widely in South American populations, displaying geographical variations in its distribution. The heterogeneous genetic contributions provided by the transatlantic parental populations that modified the Native American genomes may explain this epidemiological observation. Aiming to determine the prevalence of HHV-8 genome among healthy South American blood donors and its potential association with genetic ancestry, 772 individuals were screened by a highly sensitive PCR protocol and ancestry was assessed in 414 samples. HHV-8 DNA was significantly more prevalent among North-western Argentines than among those from the metropolitan region (P = 0.001) and Bolivians (P = 0.0008), but no differences were found when compared with Peruvians and Paraguayans. Although significant differences were observed in the ancestry components of the studied populations, no association was found in the genetic admixture between HHV-8 [+] and HHV-8 [-] samples from the same place. These results support the hypothesis of the existence of geographical factors related to HHV-8 prevalence which could be explained by the presence of specific risk factors, cultural characteristics or behaviors, probably related to contaminated saliva and/or sexual transmission. The presence of HHV-8 in South American blood units available for transfusion and an increased risk of infection in some provinces of North-western Argentina represent a hazard for immunosuppressed recipients. J. Med. Virol. 89:518-527, 2017. © 2016 Wiley Periodicals, Inc.

were 100%, 100% and 98.6%. The five patients were relapsed, 80% of relapses were occcured on 12th weeek, 15.4% in 1b and 3% in 2a or 2c. CONCLUSIONS: Most earlier studies have demonstrated, in Genotype 1b, the efficacy of eradication is poor than genotype non 1. But the virologic response is effective in any group of chronic hepatitis C infection by pegylated interferon and ribavirin combination therapy in our study. So, we think that more aggressive treatment is needed in any genotype of chronic hepatitis C and the standard regimen of pegylated interferon and ribavirin combination therapy can be effective in Korean chronic hepatitis C patients.

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