Aprendizagem baseada em casos clínicos no ensino de genética para medicina / Learning based on clinical cases in the teaching of genetics for medicine

Resumo Introdução: A necessidade premente de formar médicos autônomos e proativos implica novas abordagens didáticas e formas de mediar o conteúdo. Nesse contexto, a utilização de métodos ativos de ensino e aprendizagem pode incrementar o perfil do novo profissional. A Aprendizagem Baseada em Casos (ABC) é uma estratégia fundamentada na capacidade de o estudante relacionar teoria e prática com autonomia e tomada de decisão. A disciplina de genética aborda conteúdos que podem parecer distantes do cotidiano e da prática profissional futura, e, por isso, a necessidade de utilizar estratégias de ensino que facilitem a compreensão da aplicação desse conhecimento na prática médica. Objetivo: O presente trabalho teve por objetivo avaliar a ABC como abordagem pedagógica no processo de ensino-aprendizagem de genética para o curso de Medicina de uma instituição pública. Método: Aplicou-se um protocolo de método ativo composto por nove casos clínicos a 46 estudantes de Medicina da Universidade de Brasília que, posteriormente, foram divididos em nove grupos. Por meio de questionários, avaliaram-se o desempenho e as percepções em relação ao método. Os resultados quantitativos foram analisados por meio do teste t de Student. Resultado: O rendimento do trabalho em grupo foi estatisticamente maior em oito dos nove casos em comparação ao trabalho individual. A atividade foi considerada boa ou muito boa por 76% dos estudantes, e 90% mencionaram que houve aumento da motivação. Além disso, 71,4% destes demonstraram interesse em estudar mais sobre o assunto após a aula, 20% se consideraram capazes de ensinar o assunto a outras pessoas, e 42% avaliaram que acertariam todas ou a maioria das questões caso fossem submetidos a uma nova avaliação. Com relação ao trabalho em equipe, 38% relataram se sentir mais motivados. Por fim, 86% consideraram relevante ou muito relevante a discussão de casos clínicos para a formação profissional. Conclusão: Os resultados demostraram sucesso no uso do método ABC na abordagem de genética, porém apontaram que há dificuldades na utilização de métodos de ensino alternativos à aula expositiva. Apesar disso, fica explícito que a estratégia adotada pode levar à mobilização de conhecimentos prévios em situações da prática profissional.

Abstract Introduction: The pressing need to train autonomous and proactive professionals demands new ways of mediating content. In this context, the use of active teaching and learning methods can improve the profile of the new professional. Case-Based Learning (CBL) is a strategy based on the student's ability to relate theory and practice, with autonomy and decision-making. The discipline of Genetics addresses contents that may seem distant from everyday life and future professional practice, so it is necessary to use teaching strategies that facilitate the understanding of the application of this knowledge in medical practice. Objective: This study aimed to evaluate the CBL as a pedagogical approach in the teaching-learning process of Genetics for Medicine courses in a public institution. Methods: An active methodology protocol that consisted of nine clinical cases was applied to 46 medical students from Universidade de Brasília, who were later divided into nine groups. The performance and perceptions regarding the methodology were evaluated by questionnaires. Quantitative results were analyzed using Student's t test. Results: The performance of group work was statistically higher in 8 of 9 cases compared to individual work. Most students considered the activity good or very good (76%), but approximately half reported no increase in motivation. Moreover, 71.4% felt motivated to learn more about the subject after class and 20% considered they were able to teach the subject to others and 42% assessed they would get all or most of the questions correct if they were submitted to a new assessment. Regarding teamwork, 38% reported feeling more motivated. Finally, 86% considered the discussion of clinical cases relevant or very relevant for professional training. Final considerations: The results show, in general, success in the use of CBL on the study of genetic diseases but point out that there are difficulties in the use of alternative teaching methods to the lecture. Despite this, it is clear that learning based on clinical cases can lead to the mobilization of previous knowledge in situations of professional practice.

Ancestry analysis in rural Brazilian populations of African descent.

Rural communities comprise around 20% of Caribbean and South American populations, but are under-represented in autosomal marker databases. That deficiency is problematic for forensic genetics, as it relies on accurate descriptions of genetic variation and population structure. Brazilian populations were shaped by an intense, complex and heterogeneous process of admixture encompassing mainly Amerindians, Sub-Saharan Africans and Europeans. Quilombos are Brazilian populations with significant African descent that have remained genetically isolated to some extent from surrounding populations. In the reported study, we analyzed three rural Quilombo populations: Kalunga; Riacho de Sacutiaba e Sacutiaba; and Mocambo, along with a dataset from the HGDP-CEPH panel. Aiming to contribute to representative genetic databases of forensic interest, we analyse the three rural Quilombos populations and investigate how their genetic makeup relates to their history by analyzing an established forensic test, comprising 46 ancestry-informative (AIM) Indels. The panel was chosen for its high power in differentiating the main contributing populations of Brazil. Parental populations were selected from HGDP-CEPH data available at the forInDel allele frequency browser based on historic patterns applicable to the study populations and the amount of variability observed within and between continents. Our results show the main admixture components in the Quilombos are African and European. Those estimates are in accordance with previous analyses for both uniparental and autosomal markers. PCA, structure analysis and ancestry estimates indicate a correlation between the extent of isolation and the degree of admixture in the Quilombos: Kalunga is the most isolated population and accordingly has a higher African admixture component (67.3%). Sacutiaba is the smallest and most impacted by migration, with the highest European component (46.8%). Mocambo neighbors a Native American population and therefore has the highest Amerindian contribution (12.2%). Our results are consistent with the history and demography of Quilombos. The heterogeneity observed in these populations stresses the genetic diversity that Latin American and Caribbean rural populations can have and reiterates the need to describe them in greater detail.

Brazilian quilombos: A repository of Amerindian alleles.

OBJECTIVES: As a consequence of colonization of the Americas and decimation of the native population, an important portion of autochthonous genetic variation has been lost. However, some alleles have been incorporated into the growing populations of admixed mestizos. In this study, we evaluated the potential of African-derived communities in Brazil to be repositories of Amerindian alleles and, by extension, a source of information on American prehistory. METHODS: In this study, we describe the genetic variation of 15 ancestry informative markers (AIMs) of autosomal origin in two quilombos, Brazilian populations mainly of African descent, Santo Antônio do Guaporé (SAG; N = 31), and Santiago do Iguape (STI; N = 37). We compared the AIMs from these populations to those of other African-Brazilian populations, and to the Distrito Federal (N = 168), an urban population representative of Brazilian genetic diversity. RESULTS: By admixture analysis, we found that the SAG and STI communities have a much higher proportion (over 40%) of Amerindian contribution to their gene pools than other admixed Brazilian populations, in addition to marked African contributions. CONCLUSIONS: These results identify two living African-Brazilian populations that carry unique and important genetic information regarding Amerindian history. These populations will be extremely valuable in future investigations into American pre-history and Native American evolutionary dynamics.

The influence of erythropoietin (EPO T → G) and α-actinin-3 (ACTN3 R577X) polymorphisms on runners' responses to the dietary ingestion of antioxidant supplementation based on pequi oil ( Caryocar brasiliense Camb.): a before-after study.

BACKGROUND/AIMS: As diet can affect an individual's genes and these can affect response to supplementation, we aimed to investigate the influence of erythropoietin (EPO T→G) and α-actinin-3 (ACTN3 R577X) polymorphisms on plasma lipid peroxidation, hemogram and biochemical dosages of creatine kinase, aspartate aminotransferase, alanine aminotransferase and C-reactive protein (including high-sensitivity C-reactive protein) of runners (n = 123) before and after 14 days of 400 mg pequi oil supplementation, a natural carotenoid-rich oil, after races under closely comparable conditions. METHODS/RESULTS: Blood samples were taken immediately after racing to perform the tests. Before pequi oil supplementation, EPO polymorphism influenced erythrogram and plateletgram results, suggesting an aerobic advantage for the TG genotype and a disadvantage for the GG genotype as regards possible microvascular complications, while no association was found for ACTN3 polymorphism with endurance performance. Both polymorphisms influenced the runners' response to pequi oil: significant responses were observed for the EPO TT genotype in erythrocyte, hematocrit, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values, and for the TT and TG genotypes in red blood cell distribution width values. Significant differences were also observed in the plateletgram for the TT and TG genotypes. ACTN3 mainly influenced aspartate aminotransferase and creatine kinase values: heterozygotes had a significant reduction in aspartate aminotransferase values and homozygous individuals (XX) in creatine kinase values after pequi oil supplementation. CONCLUSION: These results emphasize the importance of studying nutrigenomic effects on athletes' performance.

Creatine kinase MM TaqI and methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms influence exercise-induced C-reactive protein levels.

Physical training induces beneficial adaptations, but exhausting exercise increases reactive oxygen species, which can cause muscular injuries with consequent inflammatory processes, implying jeopardized performance and possibly overtraining. Acute strenuous exercise almost certainly exceeds the benefits of physical activity; it can compromise performance and may contribute to increased future risk of cardiovascular disease (CVD) in athletes. Polymorphisms in the muscle-type creatine kinase (CK-MM) gene may influence performance and adaptation to training, while many potentially significant genetic variants are reported as risk factors for CVD. Therefore, we investigated the influence of polymorphisms in CK-MM TaqI and NcoI, methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and C-reactive protein (CRP G1059C) genes on exercise-induced damage and inflammation markers. Blood samples were taken immediately after a race (of at least 4 km) that took place outdoors on flat tracks, and were submitted to genotyping and biochemical evaluation of aspartate aminotransferase (AST), CK, CRP and high-sensitivity CRP (hs-CRP). CK-MM TaqI polymorphism significantly influenced results of AST, CK and hs-CRP, and an association between MTHFR C677T and A1298C with CRP level was found, although these levels did not exceed reference values. Results indicate that these polymorphisms can indirectly influence performance, contribute to higher susceptibility to exercise-induced inflammation or protection against it, and perhaps affect future risks of CVD in athletes.

Creatine kinase MM TaqI and methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms influence exercise-induced C-reactive protein levels.

Physical training induces beneficial adaptations, but exhausting exercise increases reactive oxygen species, which can cause muscular injuries with consequent inflammatory processes, implying jeopardized performance and possibly overtraining. Acute strenuous exercise almost certainly exceeds the benefits of physical activity; it can compromise performance and may contribute to increased future risk of cardiovascular disease (CVD) in athletes. Polymorphisms in the muscle-type creatine kinase (CK-MM) gene may influence performance and adaptation to training, while many potentially significant genetic variants are reported as risk factors for CVD. Therefore, we investigated the influence of polymorphisms in CK-MM TaqI and NcoI, methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and C-reactive protein (CRP G1059C) genes on exercise-induced damage and inflammation markers. Blood samples were taken immediately after a race (of at least 4 km) that took place outdoors on flat tracks, and were submitted to genotyping and biochemical evaluation of aspartate aminotransferase (AST), CK, CRP and high-sensitivity CRP (hs-CRP). CK-MM TaqI polymorphism significantly influenced results of AST, CK and hs-CRP, and an association between MTHFR C677T and A1298C with CRP level was found, although these levels did not exceed reference values. The results indicate that these polymorphisms can indirectly influence performance, contribute to higher susceptibility to exercise-induced inflammation or protection against it, and perhaps affect future risks of CVD in athletes.

Genetic polymorphisms influence runners' responses to the dietary ingestion of antioxidant supplementation based on pequi oil (Caryocar brasiliense Camb.): a before-after study.

Genes have been implicated in the levels of oxidative stress, lipids, CVD risk, immune reactivity, and performance. Pequi oil (Caryocar brasiliense) has shown anti-inflammatory and hypotensive effects, besides reducing exercise-induced DNA, tissue damages, and anisocytosis. Given that diet can interact with the human genome to influence health and disease, and because genetic variability can influence response to diet, we aim to investigate the influence of 12 gene polymorphisms on inflammatory markers, postprandial lipids, arterial pressure, and plasma lipid peroxidation of runners (N = 125), before and after 14 days of 400 mg pequi-oil supplementation, after races under closely comparable conditions. Arterial pressure was checked before races; blood samples were taken immediately after racing to perform leukogram and plateletgram, Tbars assay, lipid, and CRP dosages and genotyping. CAT, GST-M1/T1, CRP-G1059C, and MTHFR-C677T polymorphisms influenced post-pequi-oil responses in leukogram; Hp and MTHFR-C677T, in plateletgram; Hp, ACE, GSTT1, and MTHFR-A1298C, in lipid profile; MTHFR-A1298C, in C-reactive protein (CRP) levels; and Hp and MnSOD, in Tbars assay. Differences between ACE genotypes in leukogram and total cholesterol disappeared after pequi, and the same occurred for Hp and MnSOD in Tbars assay and for MTHFR-A1298C with CRP levels. Because genetic inheritance is one of the factors that drive atherosclerosis-related lipid abnormalities, results can contribute to a greater understanding of the influence of genetic polymorphisms in situations that push up free radicals. Knowledge is also expanded on how antioxidant supplementation affects an individual's genes and how athletic genetic makeup can affect the way a person responds to antioxidant supplements.

Who were the male founders of rural Brazilian Afro-derived communities? A proposal based on three populations.

BACKGROUND: Brazilian Quilombos are Afro-derived communities founded mainly by fugitive slaves between the 16(th) and 19(th) centuries; they can be recognized today by ancestral and cultural characteristics. Each of these remnant communities, however, has its own particular history, which includes the migration of non-African derived people. METHODS: The present work presents a proposal for the origin of the male founder in Brazilian quilombos based on Y-haplogroup distribution. Y haplogroups, based on 16 binary markers (92R7, SRY2627, SRY4064, SRY10831.1 and .2, M2, M3, M09, M34, M60, M89, M213, M216, P2, P3 and YAP), were analysed for 98 DNA samples from genetically unrelated men from three rural Brazilian Afro-derived communities-Mocambo, Rio das Rãs and Kalunga-in order to estimate male geographic origin. RESULTS: Data indicated significant differences among these communities. A high frequency of non-African haplogroups was observed in all communities. CONCLUSIONS: This observation suggested an admixture process that has occurred over generations and directional mating between European males and African female slaves that must have occurred on farms before the slaves escaped. This means that the admixture occurred before the slaves escaped and the foundation of the quilombo.

Superoxide dismutase, catalase, glutathione peroxidase and gluthatione S-transferases M1 and T1 gene polymorphisms in three Brazilian population groups

Antioxidants such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX1) reduce the oxidation rates in the organism. Gluthatione S-transferases (GSTs) play a vital role in phase 2 of biotransformation of many substances. Variation in the expression of these enzymes suggests individual differences for the degree of antioxidant protection and geographical differences in the distribution of these variants. We described the distribution frequency of CAT (21A/T), SOD2 (Ala9Val), GPX1 (Pro198Leu), GSTM1 and GSTT1 polymorphisms in three Brazilian population groups: Kayabi Amerindians (n = 60), Kalunga Afro-descendants (n = 72), and an urban mixed population from Federal District (n = 162). Frequencies of the variants observed in Kalunga (18 percent to 58 percent) and Federal District (33 percent to 63 percent) were similar to those observed in Euro and Afro-descendants, while in Kayabi (3 percent to 68 percent), depending on the marker, frequencies were similar to the ones found in different ethnic groups. Except for SOD2 in all population groups studied here, and for GPX1 in Kalunga, the genotypic distributions were in accordance with Hardy-Weinberg Equilibrium. These data can clarify the contribution of different ethnicities in the formation of mixed populations, such as that of Brazil. Moreover, outcomes will be valuable resources for future functional studies and for genetic studies in specific populations. If these studies are designed to comprehensively explore the role of these genetic polymorphisms in the etiology of human diseases they may help to prevent inconsistent genotype-phenotype associations in pharmacogenetic studies.

Evaluation of gene polymorphisms in exercise-induced oxidative stress and damage.

Many potentially significant genetic variants related to oxidative stress have been identified and performance in endurance sports is a multi-factorial phenotype. Thus, it was decided to investigate the influences of the haptoglobin (Hp), MnSOD (Val9Ala), CAT (21A/T), GPX1 (Pro198Leu), ACE, glutathione S-transferases M1 (GSTM1) and T1 (GSTT1) genes' polymorphisms on the oxidative stress and damage suffered by human athletes (runners). Blood samples taken immediately after a race were submitted to genotyping, comet and TBARS assays, biochemical analyses of creatine kinase (CK), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). MnSOD significantly influenced results of CK and a possible association between Hp1F-1S and Hp1S-2 genotypes with a superior TBARS values was found. Higher or lower TBARS and CK values or DNA damage also depended on the interaction between Hp and ACE or GST genotypes, indicating that MnSOD and Hp polymorphisms can be determining factors in performance, at least for runners.

Beta-globin haplotypes in normal and hemoglobinopathic individuals from Reconcavo Baiano, State of Bahia, Brazil

Five restriction site polymorphisms in the Beta-globin gene cluster (HincII-5'épsilon, HindIII-Ggama, HindIII-Agama, HincII-PsiBeta1 and HincII-3'PsiBeta1) were analyzed in three populations (n = 114) from Reconcavo Baiano, State of Bahia, Brazil. The groups included two urban populations from the towns of Cachoeira and Maragojipe and one rural Afro-descendant population, known as the "quilombo community", from Cachoeira municipality. The number of haplotypes found in the populations ranged from 10 to 13, which indicated higher diversity than in the parental populations. The haplotypes 2 (+----), 3 (----+), 4 (-+--+) and 6 (-++-+) on the BetaA chromosomes were the most common, and two haplotypes, 9 (-++++) and 14 (++--+), were found exclusively in the Maragojipe population. The other haplotypes (1, 5, 9, 11, 12, 13, 14 and 16) had lower frequencies. Restriction site analysis and the derived haplotypes indicated homogeneity among the populations. Thirty-two individuals with hemoglobinopathies (17 sickle cell disease, 12 HbSC disease and 3 HbCC disease) were also analyzed. The haplotype frequencies of these patients differed significantly from those of the general population. In the sickle cell disease subgroup, the predominant haplotypes were BEN (Benin) and CAR (Central African Republic), with frequencies of 52.9 percent and 32.4 percent, respectively. The high frequency of the BEN haplotype agreed with the historical origin of the afro-descendant population in the state of Bahia. However, this frequency differed from that of Salvador, the state capital, where the CAR and BEN haplotypes have similar frequencies, probably as a consequence of domestic slave trade and subsequent internal migrations to other regions of Brazil.

Afro-derived Brazilian populations: male genetic constitution estimated by Y-chromosomes STRs and AluYAP element polymorphisms.

The genetic constitution of Afro-derived Brazilian populations is barely studied. To improve that knowledge, we investigated the AluYAP element and five Y-chromosome STRs (DYS19, DYS390, DYS391, DYS392, and DYS393) to estimate ethnic male contribution in the constitution of four Brazilian quilombos remnants: Mocambo, Rio das Rãs, Kalunga, and Riacho de Sacutiaba. Results indicated significant differences among communities, corroborating historical information about the Brazilian settlement. We concluded that besides African contribution, there was a great European participation in the constitution of these four populations and that observed haplotype variability could be explained by gene flow to quilombos remnants and mutational events in microsatellites (STRs).

Glutathione S-transferase M1 and T1 polymorphisms in Brazilian African descendants.

The glutathione S-transferase gene family has an important role in the biotransformation and detoxification of different xenobiotics and endogenous compounds. Two polymorphic genes of this family, GSTM1 and GSTT1, present null alleles that consequently do not produce the respective enzyme when the genotype is homozygous. These polymorphisms are also interesting for population dynamics studies because they have great frequency variations among different ethnic groups and have been reported worldwide. The distribution of these alleles in urban and Amerindian populations in Brazil has been described, but none of those studies reported on African-descended rural populations. The aim of this study was to analyze the genotype frequency distribution of the GSTM1 and GSTT1 null alleles in an urban sample from the Federal District (n = 91) and in four semi-isolated African-descended populations: Mocambo (n = 55), Rio das Rãs (n = 117), Riacho de Sacutiaba (n = 34), and Kalunga (n = 68). The GSTM1 and GSTT1 null genotype frequencies in these populations range from 17% to 35% for GSTM1 and from 22% to 44% for GSTT1. These values are similar to those described in other African and African-descended populations. Despite this range, there is no distribution difference among the analyzed populations. Combined GSTM1 and GSTT1 null genotype frequencies range from 6% to 13% and are similar to European-derived populations, suggesting admixture with this ethnic group. This can be interpreted as a European contribution to these African-descended populations. Regarding the urban population in the Federal District, our results suggest an important African and European contribution.

Analysis of genetic susceptibility to mercury contamination evaluated through molecular biomarkers in at-risk Amazon Amerindian populations

We investigated Individual differences in susceptibility to methylmercury (MeHg) contamination and its relationship with polymorphisms of the detoxifying enzyme glutathione S-transferase (GST). In Brazil, some Amerindian tribes from the Amazon region have an increased level of mercury in their hair. Samples of hair and blood were taken from inhabitants of two villages in the Kayabi and Munduruku Amerindian communities to investigate mercury levels in association with genetic polymorphism of GSTs. Other molecular biological markers were also studied, such as hemoglobin, haptoglobin and glucose 6-phosphate dehydrogenase (G-6-PDH). Higher levels of mercury contamination were found in the Kayabi villagers, who had a null genotype (GSTM1 0/0, also denominated GSTM1 null) frequency of 26%, than in the Munduruku villagers, for which the null genotype frequency was 0%. Individuals with the GSTM1 null phenotype had higher concentrations of mercury in their hair than individuals with GSTM1+/+ phenotypes (F = 21.51, p < 0.0001). No association with other markers studied was observed. This study suggests that GSTM1 may be involved in the biotransformation of mercury in humans

Distribution of glutathione S-transferase GSTM1 and GSTT1 null phenotypes in Brazilian Amerindians

The distribution of glutathione S-transferase (GST) GSTM1 and GSTT1 null phenotype frequencies in two Brazilian Amerindian tribes, the Munduruku tribe from Missão Cururu village (79 individuals) and the Kayabi tribe (41 individuals), was analyzed by polymerase chain reaction (PCR) amplification. The GST null phenotype frequencies for the Munduruku sample were 0 percent for GSTM1 and 27 percent for GSTT1 while for the Kayabi sample the null phenotype frequencies were 27 percent for GSTM1 and 29 percent for GSTT1. This is the first report of the absence of the GSTM1 null phenotype in any ethnic group.

Genotoxicity evaluation of domestic sewage in a municipal wastewater treatment plant

An evaluation of the genotoxicity of domestic sewage was carried out in a municipal wastewater treatment plant. The study was carried out using Allium cepa root tip cells through cytological parameters such as aberrant cells in anaphase-telophase and the mitotic index, and the fish species Oreochromis niloticus and Tilapia rendalli, through the index of micronuclei in peripheral erythrocytes. In the Allium test, each of the four stages of the wasterwater treatment routine was analyzed, i.e., crude sewage, primary effluent, secondary effluent, and tertiary effluent. O. niloticus and T. rendalli specimens were maintained in an aquarium continuously receiving the final effluent, in an open system, before being discharged into Lake Paranoá. For micronuclei analysis, blood samples were drawn after 7, 21, 60, 102 and 142 days, respectively, in controlled conditions. The numbers of aberrant cells found in the Allium test did not differ among the four stages tested, nor when compared with the control. At all stages, the most concentrated sample was more toxic than the respective diluted samples, as demonstrated by the decreased mitotic index. Different sampling of the same group of fish revealed no increase in the micronuclei frequency, regardless of the period of exposure. A correlation between long-term exposure and micronuclei induction was not found either.

CCR5D32 mutation in three Brazilian populations of predominantly Sub-Saharan African ancestry

This study reports the frequencies of the CCR5D32 mutation of the beta-chemokine 5 gene and discusses the possible effects of past and recent gene flow in three quilombo remnants (Brazilians communities with anthropological African ancestry whose ancestors were escaped slaves): Rio das Rãs, Mocambo, and São Gonçalo in the northeastern region of Brazil. The CCR5D32 allele frequency of the Mocambo population was significantly higher (5.6 percent) than that found in the Rio das Rãs (1 percent) and São Gonçalo (0.9 percent) populations. These differences may reflect different proportions of parental populations in the founders individuals, a founder-effect and/or different histories of inter-ethnic contact. The frequency of the CCR5D32 allele in the Mocambo sample is similar to that found in those urban Brazilian populations which have a large amount of European genetic input, indicating a European contribution to the gene pool of this population and suggesting that, perhaps since its foundation, Mocambo has had a high level of admixture or experienced a founder-effect.