Genetic admixture in Brazil

We review studies from our laboratories using different molecular tools to characterize the Amerindian, European and African ancestry of Brazilians. Initially we used uniparental DNA markers to investigate the contribution of distinct Y chromosome and mitochondrial DNA lineages to present-day populations. High levels of genetic admixture and strong directional mating between European males and Amerindian and African females were unraveled. We next analyzed different types of biparental autosomal polymorphisms. Especially useful was a set of 40 insertion-deletion polymorphisms (indels) that when studied worldwide proved exquisitely sensitive in discriminating between Amerindians, Europeans and Sub-Saharan Africans. When applied to the study of Brazilians these markers confirmed extensive genomic admixture. We then studied ancestry differences in different regions by statistically controlling them to eliminate color considerations. The European ancestry was predominant in all regions studied, with proportions ranging from 60.6% in the Northeast to 77.7% in the South. We propose that the immigration of 6 million Europeans to Brazil in the 19th and 20th centuries is in large part responsible for dissipating previous ancestry dissimilarities that reflected region-specific population histories. Brazilians should be assessed individually, as 210 million human beings, and not as members of specific regions or color groups.

Analysis of sports-relevant polymorphisms in a large Brazilian cohort of top-level athletes

In recent years, there have been an increasing number of genetic variants associated with athletic phenotypes. Here, we selected a set of sports-relevant polymorphisms that have been previously suggested as genetic markers for human physical performance, and we examined their association with athletic status in a large cohort of Brazilians. We evaluated a sample of 1,622 individuals, in which 966 were nonathletes, and 656 were athletes: 328 endurance athletes and 328 power athletes. Only the AGT M268T minor allele was nominally associated with the endurance status. Conversely, we found that seven polymorphisms are more frequent in power athletes (MCT1 D490E, AGT M268T, PPARG P12A, PGC1A G482S, VEGFR2 Q472H, NOS3 C/T, and ACTN3 R577X). For all of these polymorphisms, power athletes were more likely than nonathletes or endurance athletes to carry the major allele or the homozygous genotype for the major allele. In particular, MCT1 D490E, AGT M268T, NOS3 C/T, and ACTN3 R577X showed stronger associations. Our findings support a role for these variants in the achievement of power athletic status in Brazilians: MCT1 D490E (T allele), AGT M268T (G allele), PPARG (C allele), PGC1A G482S (C allele), VEGFR2 Q472H (T allele), NOS3 C/T (T allele), and ACTN3 R577X (R allele).

Genome-wide association study of warfarin maintenance dose in a Brazilian sample

AIM

Extreme discordant phenotype and genome-wide association (GWA) approaches were combined to explore the role of genetic variants on warfarin dose requirement in Brazilians.

METHODS

Patients receiving low (≤ 20 mg/week; n = 180) or high stable warfarin doses (≥ 42.5 mg/week; n = 187) were genotyped with Affymetrix Axiom(®) Biobank arrays. Imputation was carried out using data from the combined 1000 Genomes project.

RESULTS

Genome-wide signals (p ≤ 5 × 10(-8)) were identified in the well-known VKORC1 (lead SNP, rs749671; OR: 20.4; p = 1.08 × 10(-33)) and CYP2C9 (lead SNP, rs9332238, OR: 6.8 and p = 4.4 × 10(-13)) regions. The rs9332238 polymorphism is in virtually perfect LD with CYP2C9*2 (rs1799853) and CYP2C9*3 (rs1057910). No other genome-wide significant regions were identified in the study.

CONCLUSION

We confirmed the important role of VKORC1 and CYP2C9 polymorphisms in warfarin dose. Original submitted 14 January 2015; Revision submitted 26 May 2015.

A practical approach to a low protein diet in Brazil

BACKGROUND

Chronic kidney disease (CKD) is an emerging health public problem in Brazil. Nutritional counseling with focus on protein restriction is a promising strategy to treatment of nondialysis CKD patients due its effects on slowing renal loss. However, Brazilian people have high protein intake, which is a challenge when low protein diet (LPD) should be prescribed. This review describes a practical approach to the dietetic management of nondialysis CKD patients in Brazil.

DISCUSSION

Although Brazilian cuisine varies greatly by region, Brazil has current trends of incorporating Western dietary habits, including high intake of red meat. Traditional plant-based foods, such as rice and beans, are also important contributors to the high protein content to the Brazilian diet. Thus, a successful implementation of LPD requires adaptation of these dietary habits, with reduction of portion sizes and adequate food substitution options. Intensive nutritional counseling with specialized renal dietitians is also important to improve compliance to the LPD. Moreover, the precarious health system organization and economic problems are barriers to nutritional care, which could be solved with intensive and specialized perspectives of treatment. The adherence to protein restriction is important for better metabolic and clinical control of nondialysis CKD patients. Early dietetic attention, nutrition education strategies and intensive specialized nutritional counseling are essential to achieve diet habits that promote adherence to the LPD without excluding cultural characteristics of the Brazilian diet.

Neuroticism, negative life events, and dementia in older White and Black Brazilians

OBJECTIVE

Exposure to negative life events (NLEs) and neuroticism are associated with dementia. It is unknown whether neuroticism explains or modifies the association of NLEs with dementia in older Black and White Brazilians.

METHODS

A total of 1747 decedents 65 years and older White and Black (11% Black and 23% Mixed) Brazilians, 53% women, were included in the analyses. Data were obtained in a face-to-face interview with an informant (71% their children) who knew the decedents for 47 years on average. Dementia was classified using the Clinical Dementia Rating. NLEs were assessed with a 10-item scale involving common problems (e.g., death, illness, alcoholism, and financial). Neuroticism was assessed with a 6-item neuroticism scale adapted from the NEO Five-Factor Inventory. Models adjusted for age, sex, and education. Black and mixed-race were combined in the analyses.

RESULTS

NLEs (median of 2) were more common in Blacks than Whites (2.04 vs. 1.82, p = 0.007). More NLEs increased the odds of dementia (OR = 1.112, β = 0.106, p = 0.002), similarly in Blacks and Whites (β interaction  = 0.046, p = 0.526). More NLEs were also associated with higher neuroticism (β = 0.071, p < 0.0001), in Whites but not in Blacks (β interaction  = -0.048, p = 0.006). Neuroticism was associated with higher odds of dementia (OR = 1.658, β = 0.506, p=<0.001), in Whites but not in Blacks (β interaction  = -0.420, p = 0.040). Overall, 34% of the effect of NLEs on dementia was associated with the underlying neuroticism trait in Whites (65%, Indirect OR = 1.060, p < 0.001) but no association was evident in Blacks (6%, Indirect OR = 1.008, p = 0.326). Neuroticism did not moderate the association of NLEs with dementia (OR = 0.979, β = -0.021, p = 0.717).

CONCLUSION

The association of NLEs and dementia is partially explained by neuroticism in older White but not in Blacks Brazilians.

YouTube™ as a source of tooth avulsion information: A video analysis study

BACKGROUND/AIM

Evaluate the informative content in tooth avulsion videos intended for dentists available on YouTube™ and analyse their compliance with the International Association of Dental Traumatology (IADT) guidelines 2020.

MATERIALS AND METHODS

Google Trends was used to identify the most searched term for tooth avulsion. Tooth avulsion-related videos in Brazilian Portuguese intended for dentists were searched on YouTube™ with a 12-month filter. Two raters reviewed these videos to extract their features and evaluate and qualify them with two 9-point checklists based on the IADT 2020 guidelines. The emergency steps for tooth avulsion at the accident site were assessed before, during and after clinical management; each step received 1 point if present and 0 points if absent. The final score ranged from 0 to 9 points on each checklist (18 points total), and the total score was used to classify the videos as having poor, moderate or rich content. Reliability and video quality were evaluated by an adapted version of the DISCERN tool and global quality scale (GQS), respectively. The data were analysed with the Mann-Whitney U-test, Pearson chi-square test, and the Kappa statistic (p < .05).

RESULTS

Of 60 videos, 8 were included. All were uploaded by dental professionals or undergraduate students; the average duration was 11 min (range: 0.40-65 min), and the average number of views was 56.75. Half the videos (50%) had maximum completeness scores for questions about emergency dentist referral before clinical management, and more than half (75%) had maximum completeness regarding the steps required during and after treatment. Rich videos had higher GQS scores (p = .049) without significant correlation.

CONCLUSIONS

Although most videos in Brazilian Portuguese were considered high-quality according to the IADT checklist, half of them presented partial absence of information regarding orientations at the accident site.

Familial multiple sclerosis in a Brazilian sample: Is HLA-DR15 involved in susceptibility to the disease?

BACKGROUND

The HLA-DR15 extended haplotype HLA-DRB1*15:01-DQA1*01:02-DQB1*06:02 comprises the strongest genetic risk factor for multiple sclerosis (MS). The aim of this work was to investigate whether HLA-DR15 alleles were significantly associated with the susceptibility to MS familial forms (MSf) in an admixed Brazilian population.

METHODS

Association analyses between DR15 and the clinical and demographic variables were made.

RESULTS

We have genotyped 25 familial cases. The DR15 was detected in 11/25 (44%) of them and in none of controls (P < .00001). DR15 was significantly associated to a foreign ancestor background (P = .029) and later age of onset (P = .018).

Mutational spectrum of breast cancer susceptibility genes among women ascertained in a cancer risk clinic in Northeast Brazil

PURPOSE

There is a paucity of data on the spectrum and prevalence of pathogenic variants among women of African ancestry in the Northeast region of Brazil.

METHODS

We performed BROCA panel sequencing to identify inherited loss-of-function variants in breast cancer susceptibility genes among 292 Brazilian women referred to a single institution cancer risk assessment program.

RESULTS

The study included a convenient cohort of 173 women with invasive breast cancer (cases) and 119 women who were cancer-free at the time of ascertainment. The majority of the women self-reported as African-descended (67% for cases and 90.8% for unaffected volunteers). Thirty-seven pathogenic variants were found in 36 (20.8%) patients. While the spectrum of pathogenic variants was heterogeneous, the majority (70.3%) of the pathogenic variants were detected in high-risk genes BRCA1, BRCA2, PALB2, and TP53. Pathogenic variants were also found in the ATM, BARD1, BRIP1, FAM175A, FANCM, NBN, and SLX4 genes in 6.4% of the affected women. Four recurrent pathogenic variants were detected in 11 patients of African ancestry. Only one unaffected woman had a pathogenic variant in the RAD51C gene. Different risk assessment models examined performed well in predicting risk of carrying germline loss-of-function variants in BRCA1 and/or BRCA2 in breast cancer cases.

CONCLUSION

The high prevalence and heterogenous spectrum of pathogenic variants identified among self-reported African descendants in Northeast Brazil is consistent with studies in other African ancestry populations with a high burden of aggressive young onset breast cancer. It underscores the need to integrate comprehensive cancer risk assessment and genomic testing in the management of newly diagnosed Black women with breast cancer across the African Diaspora, enabling improved cancer control in admixed underserved and understudied populations.

Prevalence and predictors of overweight and obesity in Brazilian immigrants in Massachusetts

BACKGROUND

Overweight and obesity are important risk factors for chronic non-communicable diseases, and their prevalence is on the rise worldwide. This study seeks to describe the prevalence and predictors of overweight and obesity in Brazilian immigrants living in Massachusetts, United States of America (USA).

METHODS

Modeled after a survey on behavioral risk factors for chronic disease conducted annually in Brazil (Vigilância de Fatores de Risco e Proteção para Doenças Crônicas por Inquérito Telefônico: Vigitel), Brazilian immigrants aged 18+ (n = 361) were surveyed between December 2013 and March 2014. Information was obtained from consenting participants regarding their demographic characteristics, physical activity, dietary and lifestyle habits, and other behavioral risk factors. Weight status was estimated from body mass index (BMI), calculated from self-reported height and weight data. Participants were categorized as overweight/obese if their BMI was ≥25; overweight and obese categories were combined to ensure appropriate sample size. Prevalence of overweight/obesity was estimated using STATA, and significant predictors were identified via multi-variable logistic regression. Odds ratio (OR), 95% confidence intervals (95% CI) and p-values were determined.

RESULTS

The overall prevalence of overweight/obesity in the sample was 47.6%. Significant predictors of overweight and obesity were gender (men OR 2.30, 95% CI: 1.10, 3.78; women are comparison group), working in the 3 months prior to the survey (OR 2.90, 95% CI: 1.01, 8.30), and longer duration living in the USA (OR per additional year 1.06, 95% CI: 1.02, 1.11). Significant dietary predictors of overweight/obesity included 5 or more days per week of consumption of red meat (OR red meat 3.70, 95% CI: 1.47, 9.26) or of sweetened beverages, like soft drinks also known as soda (OR soda 2.40, 95% CI: 1.00, 5.78) compared with less frequent consumption of these foods.

CONCLUSIONS

This study suggests that long duration of time lived in the USA increases odds of overweight and obesity for Brazilian immigrants living in Massachusetts. Efforts to curb increases in overweight and obesity in this population should focus not only on the men and those who work but also the women. Possible intervention measures should target soda (soft drink) and red meat consumption in Brazilian immigrants.

Low variability at the HLA-E promoter region in the Brazilian population

Little information has been reported regarding the regulatory region of the HLA-E gene. Only a proximal segment (300 bp immediately before exon 1) has been described at IMGT/HLA database. We aimed to evaluate the genetic diversity of the promoter region by PCR amplification and DNA sequencing. We observed a pattern of sequencing interruption in the same position in all samples, suggesting the presence of a secondary structure hampering the DNA polymerase sliding during the sequencing process, which was confirmed after bioinformatics analysis. Considering the promoter region evaluated (nucleotide -440 to -1), only three variation sites were found, including one new variation site at position -104, and the concomitant deletions already described at positions -187 and -186. We concluded that the promoter region of the HLA-E gene presents few and rare variable sites in this population sample; however, the double-stranded branch formation hampered the evaluation of the distant promoter by conventional sequencing.

The need for culturally-tailored smartphone applications for weight control

BACKGROUND

Approximately 35% of U.S. adults are obese, and this rate is expected to increase by almost 50% by 2030. New media such as smartphone applications (apps) provide a useful and low-cost way to disseminate weight control information. For many culturally distinctive population subgroups, however, there is currently an absence of research-tested smartphone apps for weight control.

METHODS

In this commentary, we highlight the need for culturally tailored smartphone apps for weight control and offer recommendations for further research by providing two specific examples: 1) the characteristic dietary patterns and absence of smartphone apps for weight loss for Hispanic Americans, in English and Spanish, and 2) and need for smartphone apps for weight loss for Brazilian Americans, including those who speak Portuguese.

RESULTS

Smartphone apps can be an effective intervention for improving diet and nutrition, encouraging physical activity, and reducing obesity, but few randomized controlled trials have been conducted of stand-alone smartphone apps for weight loss that focus primarily on self-monitoring of diet and physical activity. Further, there have been no published studies of apps for promoting healthy diet, better nutrition, increasing levels of physical activity, and weight loss among Hispanic Americans or Brazilian Americans.

CONCLUSIONS

Low-cost, effective e-Health interventions (healthcare practices supported by electronic processes) are needed to promote physical activity, healthy eating, and weight control in culturally distinctive subgroups of the population. For weight loss, apps should be developed by use of evidence-based approaches that relate to behavioral theories. Additional public health research is needed to identify low-cost, effective strategies for weight loss for people who have varying levels of health literacy, and for non-English speakers. Culturally tailored e-Health interventions for weight control are more likely to address the needs of individuals and increase their motivation to engage in health promoting behaviors.

Genetic diversity of Gerbich alleles in Brazilians reveals an unexpected prevalence of the GE:-2,-3,4 phenotype

BACKGROUND AND OBJECTIVES

Gerbich (GE) blood group system carries high-frequency antigens and the absence of them leads to rare phenotypes: GE:-2,3,4, GE:-2,-3,4 and GE:-2,-3,-4. Their serological differentiation is limited and misclassification of Gerbich phenotypes may occur, but this can be avoided by molecular characterization. This study aimed to characterize the molecular background responsible for rare Gerbich phenotypes in Brazilian population.

MATERIALS AND METHODS

We selected eight samples from patients with anti-Ge, six from their relatives and nine samples with normal expression of Gerbich antigens. Serological tests were performed in gel and red blood cells (RBCs) were tested with anti-Ge2 and anti-Ge3. Monocyte monolayer assay (MMA) was performed. Molecular investigation was performed with allele-specific polymerase chain reaction and DNA sequencing.

RESULTS

Patient plasma samples reacted with all commercial RBCs. Patient RBCs showed negative results with anti-Ge2 and anti-Ge3. Using MMA two of eight antibodies were clinically significant. Exon 3 was not amplified in any of the patient samples and in two samples from relatives, suggesting the presence of GE*01.-03/GE*01.-03. By sequencing, we identified the genetic variability that interferes with the definition of deletion breakpoints, thus two options of genetic structure were suggested to be responsible for the GE:-2,-3,4 phenotype.

CONCLUSION

This study showed for the first time the genetic diversity of GYPC alleles for carriers of Gerbich-negative phenotypes in a Brazilian population and showed an unexpected prevalence of the GE:-2,-3,4 phenotype. It also demonstrated the importance of using molecular tools to correctly classify Gerbich phenotypes for selection of variants in antigen-matched transfusions.

Pharmacogenomics of Antihypertensive Drugs in Brazil: recent progress and clinical implications

BACKGROUND

The available antihypertensive drugs are effective and well tolerated agents. However, only about half of patients with treated hypertension achieve appropriate blood pressure control. Genetic and non-genetic factors contribute to the interindividual variability of the therapeutic response.

OBJECTIVE

This review constitutes a comprehensive update of the pharmacogenomics of antihypertensive drugs and their clinical implications in Brazil.

RESULTS

Twenty-five studies explored the influence of gene variants on drug response in patients with primary, resistant, or gestational hypertension. Variants in BDKRB2, NOS3, PRKCA, and VEGFA influenced the response to enalapril in patients with primary hypertension. AGT and MMP2 variants were associated with high risk of resistance to antihypertensive treatment, whereas NOS2 variants were related to low risk. Moreover, NAT2 slow acetylators showed an increased response to hydralazine in patients with resistant hypertension. HMOX1, NAMPT, MMP9, NOS3 and TIMP1 variants might be markers of drug responsiveness in hypertensive or preeclamptic pregnant women. Power and replication of studies, polygenic nature of response to therapy, and treatment with multiple drugs were important challenges to be overcome for identifying genetic predictors of antihypertensive response in Brazil.

CONCLUSION

Pharmacogenomic studies in Brazilian cohorts provide some evidences of variants, mainly in pharmacodynamics genes, which influence the response to antihypertensive drugs. However, some findings are limited by cohort size or therapeutic scheme and may be influenced by interactions with other genetic and non-genetic factors. Therefore, further investigations are needed to elucidate the contribution of pharmacogenomics to the efficacy and safety of antihypertensive therapy.

Immigration Policy as a Social Determinant of Health among Brazilian Immigrants in the United States: A Narrative Review

The pervasive effects of increasingly restrictive migration policies on the health of immigrant populations in the U.S. have been well-documented, but not so much concerning the unique experiences of Brazilian immigrants, a subgroup of the Latino/a/x population. Considering that, this narrative review article employs a research design that is both conceptual and exploratory-to understand the possible connections and associations between restrictive immigration policies and negative health outcomes among Brazilian immigrants in the U.S. Findings indicate that Brazilian immigrants in the U.S. face an array of health and non-health related challenges, including racism and poor working conditions, with undocumented individuals experiencing worse outcomes. Studies highlight the complex relationship between immigration policies and health and emphasize the detrimental effects of deportation fear, healthcare access obstacles, and mental health repercussions due to hostile immigration policymaking and generalized anti-immigrant sentiment. More research is needed to understand the unique challenges faced by the Brazilian immigrant population concerning several mental and physical health outcomes.

HIV/AIDS knowledge level, awareness of public health centers and related factors: a cross-sectional study among Brazilians in Japan

BACKGROUND

Accurate information is essential so that HIV infection can be detected in time for initiation of HIV/AIDS treatment. Immigrants are at high risk for delayed HIV testing and diagnosis, but foreign residents in Japan also seem to face barriers to accessing HIV/AIDS care. We aimed to assess their knowledge level of HIV/AIDS and awareness of public health centers in Japan (PHCs), and to explore factors related to these items.

METHODS

We conducted a cross-sectional study of Brazilians, the largest group of foreigners living in Shiga, using an anonymous, self-administered questionnaire survey in Brazilian Portuguese and Japanese via the Internet and mail. A multiple logistic regression analysis was used to examine the factors related to "Knowledge of HIV/AIDS" and "Awareness of PHCs".

RESULTS

A total 182 Brazilians responded. More than half of them were beginners in Japanese. Most respondents were familiar with HIV/AIDS, but only 58% knew the existence of PHCs, and only 25% knew that HIV testing is available at PHCs free of charge and anonymously. A multiple logistic regression analysis showed that PHCs were less recognized by those with intermediate (odds ratio: 5.70, 95% confidence interval: 1.53-21.23) and beginner (odds ratio: 6.81, 95% confidence interval: 1.98-23.45) Japanese proficiency than by those with advanced.

CONCLUSIONS

This survey revealed the knowledge level of HIV/AIDS and awareness of PHC among Brazilians in Shiga. Their lack of awareness of PHCs due to language barriers may lead to delays in HIV testing among them. Therefore, it is important for PHCs to disseminate information about medical services related to HIV/AIDS in Portuguese and plain Japanese to facilitate their access to HIV testing. However, PHC efforts alone are not enough. Medical interpreters who are familiar with Brazilian culture and customs, and the clinics that employ them, could help the Brazilian community and PHCs to overcome the language barrier and provide efficient and appropriate medical care to Brazilians. This would be one way to eliminate delays in HIV testing for Brazilians in Shiga.

The seroconversion history to SARS-CoV-2 in Indigenous people from Brazil - the interplay between exposure, vaccination, and tuberculosis

The COVID-19 pandemic caused a significant loss of human lives and a worldwide decline in quality of life. Although our understanding of the pandemic has improved significantly since the beginning, the natural history of COVID-19 and its impacts on under-represented populations, such as Indigenous people from America, remain largely unknown. We performed a retrospective serological survey with two Brazilian Indigenous populations (n=624), Tupiniquim and Guarani-Mbyá. Samples were collected between September 2020 and July 2021: a period comprising the dissemination of SARS-CoV-2 variants and the beginning of COVID-19 vaccination in Brazil. Seroconversions against S and N antigens were assessed using three different commercially available ELISA kits. Samples were also used to assess the prevalence of tuberculosis (TB) in the same population (n=529). Seroconversion against SARS-CoV-2 antigens was considered positive if at least one of the three ELISA kits detected levels of specific antibodies above the threshold specified by the manufacturer. In this sense, we report 56.0% (n=349/623) of seroconverted individuals. Relative seroconversion peaked after introduction of the Coronavac vaccine in February 2021. Vaccination increased the production of anti-S IgG from 3.9% to 48.6%. Our results also indicated that 11.0% (n=46/417) of all individuals were positive for TB. Seroconversion to SARS-CoV-2 was similar between individuals with positive tuberculosis test results to those with negative test results. Most vaccinated individuals seroconverted to SARS-CoV-2, indicating that Coronavac may be as protective in individuals from these indigenous groups as observed in the general Brazilian population. COVID-19 severity was minimal regardless of incomplete vaccine coverage, suggesting that vaccination may not be the only factor protecting individuals from severe COVID-19. Tuberculosis is highly prevalent and not associated with increased seroconversion to SARS-CoV-2.