Hepatitis B virus infection in Latin America:A genomic medicine approach

Hepatitis B virus(HBV)infection is the leading cause of severe chronic liver disease.This article provides a critical view of the importance of genomic medicine for the study of HBV infection and its clinical outcomes in Latin America.Three levels of evolutionary adaptation may correlate with the clinical outcomes of HBV infection.Infections in Latin America are predominantly of genotype H in Mexico and genotype F in Central and South America;these strains have historically circulated among the indigenous population.Both genotypes appear to be linked to a benign course of disease among the native and mestizo Mexicans and native South Americans.In contrast,genotypes F,A and D are common in acute and chronic infections among mestizos with Caucasian ancestry.Hepatocellular carcinoma is rare in Mexicans,but it has been associated with genotype F1b among Argentineans.This observation illustrates the significance of ascertaining the genetic and environmental factors involved in the development of HBV-related liver disease in Latin America,which contrast with those reported in other regions of the world.

Genome-based nutrition:An intervention strategy for the prevention and treatment of obesity and nonalcoholic steatohepatitis

Obesity and nonalcoholic steatohepatitis are increasing in westernized countries, regardless of their geographiclocation. In Latin America, most countries, including Mexico, have a heterogeneous admixture genome with Amerindian, European and African ancestries. However, certain high allelic frequencies of several nutrientrelated polymorphisms may have been achieved by past gene-nutrient interactions. Such interactions may have promoted the positive selection of variants adapted to regional food sources. At present, the unbalanced diet composition of the Mexicans has led the country to a 70% prevalence rate of overweightness and obesity due to substantial changes in food habits, among other factors. International guidelines and intervention strategies may not be adequate for all populations worldwide because they do not consider disparities in genetic and environmental factors, and thus there is a need for differential prevention and management strategies. Here, we provide the rationale for an intervention strategy for the prevention and management of obesity-related diseases such as nonalcoholic steatohepatitis based on a regionalized genome-based diet. The components required to design such a diet should focus on the specific ancestry of each population around the world and the convenience of consuming traditional ethnic food.

Hepatitis C virus clearance and less liver damage in patients with high cholesterol, low-density lipoprotein cholesterol and APOE ε4 allele

BACKGROUND Cholesterol is related to improvements in the rate of sustained virological response and a robust immune response against the hepatitis C virus(HCV).APOE gene polymorphisms regulate cholesterol levels modifying the course of the HCV infection.The relationship between cholesterol,APOE alleles,and the outcome of HCV infection has not been evaluated in the admixed population of Mexico.AIM To investigate the role of APOE-ε2,-ε3,and-ε4 alleles and the metabolic profile in the outcome of HCV infection.METHODS A total of 299 treatment-na?ve HCV patients were included in this retrospective study.Patients were stratified in chronic hepatitis C(CHC)(n=206)and spontaneous clearance(SC)(n=93).A clinical record was registered.Biochemical tests were assessed by dry chemistry assay.APOE genotypes were determined using a Real-Time polymerase chain reaction assay.RESULTS Total cholesterol,low-density lipoprotein cholesterol(LDL-c),triglycerides,and hypercholesterolemia were higher in SC than CHC patients as well as the frequency of the APOEε4 allele(12.4%vs 7.3%).SC patients were overweight(54.8%).Theε4 allele was associated with SC(OR=0.55,95%CI:0.31-0.98,P=0.042)and mild fibrosis(F1-F2)in CHC patients(OR 0.091,95%CI 0.01-0.75,P=0.020).LDL-c≥101.5 mg/dL(OR=0.20,95%CI:0.10-0.41,P<0.001)and BMI≥26.6 kg/m2(OR=0.37,95%CI:0.18-0.76,P<0.001)were associated with SC status;while ALT≥50.5 IU/L was negatively associated(OR=5.67,95%CI:2.69-11.97,P<0.001).CONCLUSION In SC patients,the APOEε4 allele and LDL-c conferred a protective effect in the course of the HCV infection in the context of excess body weight.

Differential distribution of gene polymorphisms associated with hypercholesterolemia,hypertriglyceridemia,and hypoalphalipoproteinemia among Native American and Mestizo Mexicans

BACKGROUND Dyslipidemias are metabolic abnormalities associated with chronic diseases caused by genetic and environmental factors.The Mexican population displays regional differences according to ethnicity with an impact on the type of dyslipidemia.AIM To define the main dyslipidemias,the frequency of lipid-related risk alleles,and their association with hyperlipidemic states among different ethnic groups in West Mexico.METHODS In a retrospective study,1324 adults were selected to compare dyslipidemias and lipid-related gene polymorphisms.Demographic,clinical,and laboratory data were collected.A subgroup of 196 normal weight subjects without impaired glucose was selected for the association analyses.Genotyping was determined by allelic discrimination assay.RESULTS Hypercholesterolemia was the most prevalent dyslipidemia(42.3%).The frequency of the risk alleles associated with hypoalphalipoproteinemia(ABCA1)and hypercholesterolemia(APOE,LDLR)was higher in the Native Americans(P=0.047).In contrast,the Mestizos with European ancestry showed a higher frequency of the risk alleles for hypertriglyceridemia(APOE2,MTTP)(P=0.045).In normal weight Mestizo subjects,the APOB TT and LDLR GG genotypes were associated risk factors for hypercholesterolemia(OR=5.33,95%CI:1.537-18.502,P=0.008 and OR=3.90,95%CI:1.042-14.583,P=0.043,respectively),and displayed an increase in low-density lipoprotein cholesterol levels(APOB:β=40.39,95%CI:14.415-66.366,P=0.004;LDLR:β=20.77,95%CI:5.763-35.784,P=0.007).CONCLUSION Gene polymorphisms and dyslipidemias showed a differential distribution.Regional primary health care strategies are required to mitigate their prevalence considering the genetic and environmental features which could have important implications for personalized medicine within the new era of precision medicine.