Leukocyte telomere length (LTL) varies significantly across human populations, with individuals of African ancestry having longer LTL than non-Africans. However, the genetic and environmental drivers of LTL variation in Africans remain largely unknown. We report here on the relationship between LTL, genetics, and a variety of environmental and climatic factors in ethnically diverse African adults (n = 1,818) originating from Botswana, Tanzania, Ethiopia, and Cameroon.
View Article and Find Full Text PDFBackground: Besides regulatory learning skills, learning also requires students to relate to their social context and negotiate it as they transition and adjust to medical training. As such, there is a need to consider and explore the role of social and cultural aspects in student learning, particularly in problem-based learning, where the learning paradigm differs from what most students have previously experienced. In this article, we report on the findings of a study exploring first-year medical students' experiences during the first semester of an undergraduate problem-based learning medical program at an African medical school.
View Article and Find Full Text PDFGene-editing research is a complex science and foreign in most communities including Botswana. Adopting a qualitative deliberative framework with 109 participants from 7 selected ethnic communities in Botswana, we explored the perceptions of local communities on cultural values, norms, and beliefs that may motivate or deter likely participation in the use of gene-editing related research. What emerged as the ethnic community's motivators for research participation include the potential for gene-editing technologies to promote access to individualized medications, and the possibility of protecting family members from genetic related diseases.
View Article and Find Full Text PDFSkin color is highly variable in Africans, yet little is known about the underlying molecular mechanism. Here we applied massively parallel reporter assays to screen 1,157 candidate variants influencing skin pigmentation in Africans and identified 165 single-nucleotide polymorphisms showing differential regulatory activities between alleles. We combine Hi-C, genome editing and melanin assays to identify regulatory elements for MFSD12, HMG20B, OCA2, MITF, LEF1, TRPS1, BLOC1S6 and CYB561A3 that impact melanin levels in vitro and modulate human skin color.
View Article and Find Full Text PDFComparisons of Neanderthal genomes to anatomically modern human (AMH) genomes show a history of Neanderthal-to-AMH introgression stemming from interbreeding after the migration of AMHs from Africa to Eurasia. All non-sub-Saharan African AMHs have genomic regions genetically similar to Neanderthals that descend from this introgression. Regions of the genome with Neanderthal similarities have also been identified in sub-Saharan African populations, but their origins have been unclear.
View Article and Find Full Text PDFUnlabelled: While the evaluation of learning development interventions needs to be considered carefully and included at the curriculum design stage, there is limited literature on the actual design of interventions, especially on how these designs evolve and improve over time. This paper describes the evolution of a learning development program intended to support first-year medical students adjusting to a problem-based learning curriculum. We used a design-based research approach, articulating our theoretical grounding and incorporating students' voices to develop an "optimal" intervention for the specific challenges in our context.
View Article and Find Full Text PDFHLA allelic variation has been well studied and documented in many parts of the world. However, African populations have been relatively under-represented in studies of HLA variation. We have characterized HLA variation from 489 individuals belonging to 13 ethnically diverse populations from rural communities from the African countries of Botswana, Cameroon, Ethiopia, and Tanzania, known to practice traditional subsistence lifestyles using next generation sequencing (Illumina) and long-reads from Oxford Nanopore Technologies.
View Article and Find Full Text PDFWe conduct high coverage (>30×) whole-genome sequencing of 180 individuals from 12 indigenous African populations. We identify millions of unreported variants, many predicted to be functionally important. We observe that the ancestors of southern African San and central African rainforest hunter-gatherers (RHG) diverged from other populations >200 kya and maintained a large effective population size.
View Article and Find Full Text PDFis a newly established family of circular Rep-encoding single-stranded (CRESS) DNA viruses found in the human ororespiratory tract. Redondoviruses were previously found in ∼15% of respiratory specimens from U.S.
View Article and Find Full Text PDFWe investigated global patterns of genetic variation and signatures of natural selection at host genes relevant to SARS-CoV-2 infection ( , and ). We analyzed novel data from 2,012 ethnically diverse Africans and 15,997 individuals of European and African ancestry with electronic health records, and integrated with global data from the 1000GP. At , we identified 41 non-synonymous variants that were rare in most populations, several of which impact protein function.
View Article and Find Full Text PDFWe investigated global patterns of genetic variation and signatures of natural selection at host genes relevant to SARS-CoV-2 infection (, , , and ). We analyzed novel data from 2,012 ethnically diverse Africans and 15,997 individuals of European and African ancestry with electronic health records, and integrated with global data from the 1000GP. At , we identified 41 non-synonymous variants that were rare in most populations, several of which impact protein function.
View Article and Find Full Text PDFLeukocyte telomere length (LTL) might be causal in cardiovascular disease and major cancers. To elucidate the roles of genetics and geography in LTL variability across humans, we compared LTL measured in 1295 sub-Saharan Africans (SSAs) with 559 African-Americans (AAms) and 2464 European-Americans (EAms). LTL differed significantly across SSAs (P = 0.
View Article and Find Full Text PDFPopulations in sub-Saharan Africa have historically been exposed to intense selection from chronic infection with falciparum malaria. Interestingly, populations with the highest malaria intensity can be identified by the increased occurrence of endemic Burkitt Lymphoma (eBL), a pediatric cancer that affects populations with intense malaria exposure, in the so called "eBL belt" in sub-Saharan Africa. However, the effects of intense malaria exposure and sub-Saharan populations' genetic histories remain poorly explored.
View Article and Find Full Text PDFContext: The journey through medical school can be challenging, especially for undergraduate medical students who must deal with a demanding curriculum, coupled with the demands of transitioning into adulthood. Despite experiencing learning challenges, most students succeed with appropriate learning support. Many medical schools offer learning support programmes, particularly in the latter years, but it has been suggested that such support could be more beneficial, especially during the initial years.
View Article and Find Full Text PDFDespite the wide range of skin pigmentation in humans, little is known about its genetic basis in global populations. Examining ethnically diverse African genomes, we identify variants in or near , , , , , and that are significantly associated with skin pigmentation. Genetic evidence indicates that the light pigmentation variant at was introduced into East Africa by gene flow from non-Africans.
View Article and Find Full Text PDFBackground: Sub-Saharan Africa has a greater share of the global burden of disease, poverty, and inadequate human resources for health compared with other regions of the world. Botswana, as other regional countries, is failing to successfully recruit and retain academics at its medical school.
Objectives: To document the medical school's staff recruitment and retention trends and challenges, and to propose possible solutions.
Having adequate numbers of qualified human resources for health is essential for any effective health care system. However, there is a global shortage of skilled health care workers, especially in Sub-Saharan African countries. This shortage is exacerbated by a disproportionately high rate of infectious diseases, the burden of emerging chronic, noncommunicable diseases, and the emigration of medical doctors.
View Article and Find Full Text PDFBackground: Although there is a high incidence of tendon injury as a result of participation in physical activity, the mechanisms responsible for such injuries are poorly understood. Investigators have suggested that some people may have a genetic predisposition to develop tendon injuries; in particular, genes on the tip of the long arm of chromosome 9 might, at least in part, be associated with this condition. The tenascin-C gene, which has been mapped to chromosome 9q32-q34, encodes for a structural component of tendons.
View Article and Find Full Text PDFThe purpose of this study was to determine if runners who completed a 100 km ultramarathon race in the fastest times changed their running speeds differently compared to those runners who ran an overall slower race. Times were taken from the race results of the 1995 100 km IAU World Challenge in Winschoten, Netherlands. Race times and 10 km split times were analyzed.
View Article and Find Full Text PDFPurpose: Several studies have suggested that the insertion (I) variant rather than the deletion (D) variant of the human angiotensin-converting enzyme (ACE) gene is associated with elite endurance performance. The aim of this study was to determine whether the ID polymorphism is associated with the performance of the fastest finishers of the South African Ironman Triathlons.
Methods: A total of 447 Caucasian male triathletes of a variety of nationalities and athletic ability who completed either the 2000 or 2001 South African Ironman Triathlons and 199 Caucasian male control subjects were genotyped for the ACE ID polymorphism.