Ancestry, diversity, and genetics of health-related traits in African-derived communities (quilombos) from Brazil.

Brazilian quilombos are communities formed by enslaved Africans and their descendants all over the country during slavery and shortly after its abolition. Quilombos harbor a great fraction of the largely unknown genetic diversity of the African diaspora in Brazil. Thus, genetic studies in quilombos have the potential to provide important insights not only into the African roots of the Brazilian population but also into the genetic bases of complex traits and human adaptation to diverse environments. This review summarizes the main results of genetic studies performed on quilombos so far. Here, we analyzed the patterns of African, Amerindian, European, and subcontinental ancestry (within Africa) of quilombos from the five different geographic regions of Brazil. In addition, uniparental markers (from the mtDNA and the Y chromosome) studies are analyzed together to reveal demographic processes and sex-biased admixture that occurred during the formation of these unique populations. Lastly, the prevalence of known malaria-adaptive African mutations and other African-specific variants discovered in quilombos, as well as the genetic bases of health-related traits, are discussed here, together with their implication for the health of populations of African descent.

Problemas morais e/ou éticos em comitês de ética em pesquisa / Moral and/or ethical issues in research ethics committees / Problemas morales y/o éticos en los comités de ética de investigación

Resumo O objetivo do estudo é analisar problemas morais e/ou éticos vivenciados por membros de comitês de ética em pesquisa durante suas atividades e as estratégias utilizadas para solucionar esses problemas. Trata-se de pesquisa de abordagem qualitativa, com participação de 39 membros que atuavam em comitês em Salvador/BA, Brasil. Os dados foram coletados em outubro de 2020 por questionário on-line autoaplicado na plataforma Google Forms. Os resultados evidenciaram: vivências de conflitos de interesses e de valores, bem como dilemas; e utilização de trocas de experiências e compartilhamento de ideias e opiniões como estratégias para solucionar esses problemas. Conclui-se que os membros desses comitês vivenciam problemas morais e/ou éticos e buscam solucioná-los por meio de estratégias que favorecem o desenvolvimento de pesquisas conforme critérios éticos e metodológicos adequados.

Abstract The objective of the study is to analyze moral and/or ethical issues experienced by members of research ethics committees when performing their activities and the strategies used to deal with those issues. This is a qualitative study with 39 individuals that participated in committees in Salvador, Bahia, Brazil. Data were collected in October 2020 using a self-administered online questionnaire developed using Google Forms. Results showed that participants underwent conflicts of interests and values, and also faced dilemmas, and the strategies used to deal with those issues were exchanging of experiences and sharing of ideas and opinions. It is concluded that members of such committees experience moral and/or ethical issues and seek to deal with them via strategies that favor the development of research according to appropriate ethical and methodological criteria.

Resumen El objetivo del estudio es analizar los problemas morales o éticos experimentados por los miembros de los comités de ética de investigación durante sus actividades y las estrategias que utilizan para resolver dichos problemas. Se trata de una investigación de enfoque cualitativo, con la participación de 39 miembros que actuaban en comités en Salvador, Bahía, Brasil. Los datos se recopilaron en octubre del 2020 por medio de un cuestionario en línea autoadministrado en la plataforma Google Forms. Los resultados mostraron experiencias de conflictos de intereses y valores, así como dilemas; y el intercambio de experiencias, ideas y opiniones como estrategias para solucionar dichos problemas. Se concluye que los miembros de estos comités experimentan problemas morales o éticos y tratan de solucionarlos mediante estrategias que favorezcan el desarrollo de investigaciones de acuerdo con criterios éticos y metodológicos adecuados.

The D allele of angiotensin-converting enzyme gene is associated with a worse autonomic heart control in community-based older adults.

The relationship between the Renin-Angiotensin-Aldosterone System (RAAS) and modulation of the Autonomic Nervous System (ANS) is reported as complex and bidirectional. Thus, the present study aimed to compare autonomous heart control, through symbolic analysis parameters, in the older adults carrying different ACE I/D gene polymorphisms (rs4646994). Two hundred four older adults comprised the study population and were grouped according to the ACE I/D gene polymorphism: II + ID genotype and DD genotype. Successive RR intervals were recorded along 5 min and analyzed with Symbolic Analysis (SA) method. 0 V%, 1 V% and 2 V% patterns were quantified and compared between groups. A linear mixed model analysis was used to determine between-group differences in symbolic analysis parameters (0 V%, 1 V% and 2 V%), taken groups as fixed factor and sex, use of ACE inhibitors and Angiotensin II receptor type I blockers as random factors. The Bayesian analysis was carried out to check the magnitude of the evidence. The results of this study indicate that older adults carrying the DD genotype have statistically greater sympathetic modulation (0 V%) and poor sympathovagal balance (1 V%), but the Bayesian analysis indicate only an anecdotal effect. Sympathetic predominance is recognized a worrying condition, since may predisposes to cardiovascular risk.

Improving the comprehension of sarcopenic state determinants: An multivariate approach involving hormonal, nutritional, lifestyle and genetic variables.

It is known that sarcopenia is a multifaceted phenomenon, which involves genetic, nutritional, hormonal and living habits aspects. Then, an integrated analysis, as a multivariate approach, could improve the comprehension about the determinants of sarcopenic state in old adults. The present study aimed to investigate the interaction among serum vitamin D, daily caloric and protein intake, lifestyle habits, ACE I/D gene polymorphism and sarcopenic state in community-dwelling old adults. One hundred one community-dwelling old adults were clinically stratified as sarcopenic or non-sarcopenic. Serum vitamin D, daily caloric and protein intake, lifestyle habits (smoking, physical activity level and sedentary behavior) and ACE I/D gene polymorphism were recorded. A multivariate logistic regression technique was applied to investigate the interaction among the selected independent variables and the sarcopenic state. The independent variables age, smoking, serum Vitamin D and ACE I/D polymorphism achieved the statistical criteria to be inserted in the multivariate analysis. After a stepwise procedure from the multivariate logistic regression, the variables age, serum Vitamin D and ACE I/D polymorphism remained, together, in the final model. Sarcopenic state was significantly associated to older age, II-genotype and low serum Vitamin D in old adults from 60 years old.

Implications of the admixture process in skin color molecular assessment.

The understanding of the complex genotype-phenotype architecture of human pigmentation has clear implications for the evolutionary history of humans, as well as for medical and forensic practices. Although dozens of genes have previously been associated with human skin color, knowledge about this trait remains incomplete. In particular, studies focusing on populations outside the European-North American axis are rare, and, until now, admixed populations have seldom been considered. The present study was designed to help fill this gap. Our objective was to evaluate possible associations of 18 single nucleotide polymorphisms (SNPs), located within nine genes, and one pseudogene with the Melanin Index (MI) in two admixed Brazilian populations (Gaucho, N = 352; Baiano, N = 148) with different histories of geographic and ethnic colonization. Of the total sample, four markers were found to be significantly associated with skin color, but only two (SLC24A5 rs1426654, and SLC45A2 rs16891982) were consistently associated with MI in both samples (Gaucho and Baiano). Therefore, only these 2 SNPs should be preliminarily considered to have forensic significance because they consistently showed the association independently of the admixture level of the populations studied. We do not discard that the other two markers (HERC2 rs1129038 and TYR rs1126809) might be also relevant to admixed samples, but additional studies are necessary to confirm the real importance of these markers for skin pigmentation. Finally, our study shows associations of some SNPs with MI in a modern Brazilian admixed sample, with possible applications in forensic genetics. Some classical genetic markers in Euro-North American populations are not associated with MI in our sample. Our results point out the relevance of considering population differences in selecting an appropriate set of SNPs as phenotype predictors in forensic practice.

Craniofacial features of patients with sickle cell anemia and sickle cell trait.

OBJECTIVE: To identify the craniofacial characteristics of patients with sickle cell trait (SCT) and sickle cell anemia (SCA) and to compare these measurements with those of nonaffected subjects. MATERIALS AND METHODS: Clinically normal patients and those with SCT and SCA were evaluated in this study. The patients were divided into three groups: normal (control), SCA, and SCT (n  =  with 15 in each group). Inclusion criteria were SCA or SCT verified by laboratory methods and no treatment with fixed orthodontics or facial orthopedics. Lateral cephalometric radiographs were carried out and were used to obtain angular and linear measurements of anatomic structures displayed. All markings and measurements were performed by a single examiner. RESULTS: The average ANB was increased in groups with SCA (5.47 ± 2.0°) and SCT (3.80 ± 1.4°), indicating a tendency to Class II. The mean SNA angle was 83.0 ± 3.8° and 82.1±3.5° for SCA and SCT, indicating a proper positioning of the jaw from the skull base. There was an interaction between the group and sex factors for the variable SN-GoGn; measures were higher for men in the SCA group. CONCLUSION: Patients with SCA and SCT exhibited characteristics of Class II skeletal pattern because of mandibular retrusion. Most patients showed no compensatory maxillary expansion, which was determined by the normal jaw length and absence of maxillary protrusion.

Glomerular filtration rate is altered in children with sickle cell disease: a comparison between Hb SS and Hb SC.

BACKGROUND: Renal failure is common among older patients with sickle cell disease; this is preceded by subclinical glomerular hyperfiltration. Data about renal function of adults with sickle cell disease have been reported, but data on children is scarce, especially when comparing heterozygotic and homozygotic patients. OBJECTIVE: The goal of this study was to investigate the glomerular filtration rate of heterozygotic and homozygotic children with sickle cell disease. METHODS: The glomerular filtration rate of 11 children with sickle cell disease [7 homozygotic (SS) and 4 heterozygotic (SC)] with a mean age of 11 years (standard deviation: ± 5 years) was evaluated using standard laboratory techniques. Results are presented as descriptive analysis. RESULTS: Our results suggest that glomerular hyperfiltration is present in children with sickle cell disease; this is more evident in homozygotic than heterozygotic children. CONCLUSION: There is evidence of a need to monitor the renal function of children with sickle cell disease when special attention should be paid to homozygotic patients.

Glomerular filtration rate is altered in children with sickle cell disease: a comparison between Hb SS and Hb SC

BACKGROUND Renal failure is common among older patients with sickle cell disease; this is preceded by subclinical glomerular hyperfiltration. Data about renal function of adults with sickle cell disease have been reported, but data on children is scarce, especially when comparing heterozygotic and homozygotic patients. OBJECTIVE The goal of this study was to investigate the glomerular filtration rate of heterozygotic and homozygotic children with sickle cell disease. METHODS The glomerular filtration rate of 11 children with sickle cell disease [7 homozygotic (SS) and 4 heterozygotic (SC)] with a mean age of 11 years (standard deviation: ± 5 years) was evaluated using standard laboratory techniques. Results are presented as descriptive analysis. RESULTS Our results suggest that glomerular hyperfiltration is present in children with sickle cell disease; this is more evident in homozygotic than heterozygotic children. CONCLUSION There is evidence of a need to monitor the renal function of children with sickle cell disease when special attention should be paid to homozygotic patients.

Family profiles of mentally disabled individuals in an institution in Jequié - BA / Perfil das famílias de portadores de deficiência mental institucionalizados na cidade de Jequié - BA

Background: The study of mental disablement characterization in Brazil is rare, specially in Northeast. Methods: A questionnaire has been applied in 32.73% of the institutionalized mental disabled' families in Jequié - BA. Data analysis have been done using descriptive statistics. Results: The individuals are 14.34 ± 7.55 years old and sex ratio of 0.38 (1F:2.6M). The average parental age was 38 ± 12.01 years old for the fathers and 29.87 ± 8.31 years old for the mothers. Existence of family history of mental disablement and congenitals defects in 27.78% and 5.56% (respectively) of the analyzed cases. Discussion: The predominance of males should be explained by various types of mental disablement associated to X chromosome. From the studied sample, it is not too obvious the relation between high parental age and mental disablement occurrence. The familiar recurrence of mental disablement and congenital defects is higher than in others studies. Conclusion: The analyzed data reinforce the need to investigate the genetic factors related to mental disablement and the perform cytogenetic tests of the individuals and their parents, for genetic counseling.

Microsatellite studies on an isolated population of African descent in the Brazilian state of Bahia

The African descent population of the Bananal community in the Brazilian state of Bahia (BA) was characterized as a genetic isolate and analyzed for some short tandem repeat (STR) microsatellite autosomic polymorphic loci (CSF1PO, TH01, TPOX, F13A1, FESFPS and vWA). These genetic variants were further compared to data obtained from an urban sample from the town of Jequié (BA) regarding demographic and anthropogenetic aspects. The Bananal sample comprised 32 unrelated individuals whereas Jequié was represented by 76 individuals. The Bananal Negroid Phenotypic Index (NPI) was 0.98 and the Negroid Cultural Index (NCI) 0.24. Consanguineous marriages occurred at a frequency of 34.61 percent and the F value was 0.0126. All six loci studied were in Hardy-Weinberg Equilibrium (p > 0.05). The genotypic and allele frequencies of the CSF1PO and vWA loci were similar. In the Bananal population the genic diversity of the THO1 locus was 66.8 percent and that of the F13A1 locus was 83.7 percent. The estimated ethnic racial admixture was 81 percent African and 19 percent Amerindian. The multiple correlation coefficient (R²) indicated adequate adaptation (99 percent). Total genetic variation for the six loci was 82.9 percent with an index of 6.7 percent for population subdivision (G ST' = 0.067). Anthropologic data and results obtained from the allele frequencies of the loci studied are indicative of a genetic isolate in Bananal, reminiscent of the a 'quilombo community' (i.e. one founded by run away slaves).

Mating types in a mixed and multicultural population of Salvador, Brazil

Um total de 982 casais de Salvador, BA, foi classificado de acordo com sobrenome, nível educacional, ocupaçäo, religiäo (passada e presente), raça e consangüinidade. Verificou-se uma tendência geral para a homogamia com referência a todos os ítens, exceto sobrenomes. Uma vez que os sobrenomes estäo associados à raça, esse fato mostra que a populaçäo está mais próxima da panmixia - quando se consideram características näo relacionadas à cor e aos traços fisionômicos - do que seria sugerido apenas pela consideraçäo da homogamia racial. Algumas preferências heterogâmicas, relativamente à raça, também foram verificadas (cada categoria de homem com a categoria mais próxima e mais clara de mulher; mulheres mulatas claras com homens brancos). A freqüência de casamentos consangüíneos diminui à medida em que aumenta a mistura negra; esse fato pode ser devido a diferenciais socioeconômicos. O grau de endocruzamento mostra uma queda com o tempo na populaçäo geral