Population-specific variations in KCNH2 predispose patients to delayed ventricular repolarization upon dihydroartemisinin-piperaquine therapy

Funding Information: The study was supported by European and Developing Countries Clinical Trial Partnership (grant number RIA2017T-2018), Medicines for Malaria Venture (Geneva, Switzerland), UK Medical Research Council, Swedish International Development Cooperation Agency, German Ministry for Education and Research, University Claude Bernard (Lyon, France), Malaria Research and Training Centre (Bamako, Mali), Centre National de Recherche et de Formation sur le Paludisme (Burkina Faso), Institut de Recherche en Sciences de la Sant. (Bobo-Dioulasso, Burkina Faso), and Centre National de Formation et de Recherche en Sant. Rurale (Republic of Guinea). In addition, the authors received support from the Swedish Research Council (grant numbers 2019-01837, 2021-02801, 2021-05666, and 2021-06048), the Grants, Innovation and Product Development Unit of the South African Medical Research Council with funds received from Novartis and GSK R&D for Project Africa GRADIENT (grant numbers GSKNVS2/202101/004), the Robert Bosch Foundation, Stuttgart, Germany, and Conselho Nacional de Desenvolvimento Cient\u00EDfico e Tecnol\u00F3gico (CNPq), Brazil (grant number 200075/2022\u20135). T.N.S. is a CNPq Research Productivity Fellow. M.D.C. performed sequencing, analyzed the data, and conducted statistical analyses. Y.Z. conducted computational variant analyses. M.M.T. was involved in the acquisition of drug concentrations. A.D. and S.S. contributed to bioinformatics analyses. N.O. was the cardiologist responsible for cardiac toxicity assessment. A.H.T, M.L.A., B.F., and I.S. oversaw clinical patient recruitment and management. A.A.D. coordinated and oversaw the WANECAM study and critically reviewed the manuscript. P.J.G. and V.M.L designed and supervised the study. M.D.C. and V.M.L. wrote the manuscript. All authors read, reviewed, and approved of the final version of the manuscript. Funding Information: The study was supported by European and Developing Countries Clinical Trial Partnership (grant number RIA2017T-2018), Medicines for Malaria Venture (Geneva, Switzerland), UK Medical Research Council, Swedish International Development Cooperation Agency, German Ministry for Education and Research, University Claude Bernard (Lyon, France), Malaria Research and Training Centre (Bamako, Mali), Centre National de Recherche et de Formation sur le Paludisme (Burkina Faso), Institut de Recherche en Sciences de la Sant. (Bobo-Dioulasso, Burkina Faso), and Centre National de Formation et de Recherche en Sant. Rurale (Republic of Guinea). In addition, the authors received support from the Swedish Research Council (grant numbers 2019-01837, 2021-02801, 2021-05666, and 2021-06048), the Grants, Innovation and Product Development Unit of the South African Medical Research Council with funds received from Novartis and GSK R&D for Project Africa GRADIENT (grant numbers GSKNVS2/202101/004), the Robert Bosch Foundation, Stuttgart, Germany, and Conselho Nacional de Desenvolvimento e Tecnol\u00F3gico (CNPq), Brazil (grant number 200075/2022\u20135). T.N.S. is a CNPq Research Productivity Fellow. Publisher Copyright: Copyright © 2024 Camara et al.Dihydroartemisinin-piperaquine is efficacious for the treatment of uncomplicated malaria and its use is increasing globally. Despite the positive results in fighting malaria, inhibition of the Kv11.1 channel (hERG; encoded by the KCNH2 gene) by piperaquine has raised concerns about cardiac safety. Whether genetic factors could modulate the risk of piperaquine-mediated QT prolongations remained unclear. Here, we first profiled the genetic landscape of KCNH2 variability using data from 141,614 individuals. Overall, we found 1,007 exonic variants distributed over the entire gene body, 555 of which were missense. By optimizing the gene-specific parametrization of 16 partly orthogonal computational algorithms, we developed a KCNH2-specific ensemble classifier that identified a total of 116 putatively deleterious missense variations. To evaluate the clinical relevance of KCNH2 variability, we then sequenced 293 Malian patients with uncomplicated malaria and identified 13 variations within the voltage sensing and pore domains of Kv11.1 that directly interact with channel blockers. Cross-referencing of genetic and electrocardiographic data before and after piperaquine exposure revealed that carriers of two common variants, rs1805121 and rs41314375, experienced significantly higher QT prolongations (ΔQTc of 41.8 ms and 61 ms, respectively, vs 14.4 ms in controls) with more than 50% of carriers having increases in QTc >30 ms. Furthermore, we identified three carriers of rare population-specific variations who experienced clinically relevant delayed ventricular repolarization. Combined, our results map population-scale genetic variability of KCNH2 and identify genetic biomarkers for piperaquine-induced QT prolongation that could help to flag at-risk patients and optimize efficacy and adherence to antimalarial therapy.publishersversionpublishe

Impact of different mass drug administration strategies for gaining and sustaining control of <i>Schistosoma mansoni</i> and <i>Schistosoma haematobium</i> infection in Africa

This report summarizes the design and outcomes of randomized controlled operational research trials performed by the Bill & Melinda Gates Foundation-funded Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) from 2009 to 2019. Their goal was to define the effectiveness and test the limitations of current WHO-recommended schistosomiasis control protocols by performing large-scale pragmatic trials to compare the impact of different schedules and coverage regimens of praziquantel mass drug administration (MDA). Although there were limitations to study designs and performance, analysis of their primary outcomes confirmed that all tested regimens of praziquantel MDA significantly reduced local; Schistosoma; infection prevalence and intensity among school-age children. Secondary analysis suggested that outcomes in locations receiving four annual rounds of MDA were better than those in communities that had treatment holiday years, in which no praziquantel MDA was given. Statistical significance of differences was obscured by a wider-than-expected variation in community-level responses to MDA, defining a persistent hot spot obstacle to MDA success. No MDA schedule led to elimination of infection, even in those communities that started at low prevalence of infection, and it is likely that programs aiming for elimination of transmission will need to add supplemental interventions (e.g., snail control, improvement in water, sanitation and hygiene, and behavior change interventions) to achieve that next stage of control. Recommendations for future implementation research, including exploration of the value of earlier program impact assessment combined with intensification of intervention in hot spot locations, are discussed

Persistent Submicroscopic Plasmodium falciparum Parasitemia 72 Hours after Treatment with Artemether-Lumefantrine Predicts 42-Day Treatment Failure in Mali and Burkina Faso.

A recent randomized controlled trial, the WANECAM (West African Network for Clinical Trials of Antimalarial Drugs) trial, conducted at seven centers in West Africa, found that artemether-lumefantrine, artesunate-amodiaquine, pyronaridine-artesunate, and dihydroartemisinin-piperaquine all displayed good efficacy. However, artemether-lumefantrine was associated with a shorter interval between clinical episodes than the other regimens. In a further comparison of these therapies, we identified cases of persisting submicroscopic parasitemia by quantitative PCR (qPCR) at 72 h posttreatment among WANECAM participants from 5 sites in Mali and Burkina Faso, and we compared treatment outcomes for this group to those with complete parasite clearance by 72 h. Among 552 evaluable patients, 17.7% had qPCR-detectable parasitemia at 72 h during their first treatment episode. This proportion varied among sites, reflecting differences in malaria transmission intensity, but did not differ among pooled drug treatment groups. However, patients who received artemether-lumefantrine and were qPCR positive at 72 h were significantly more likely to have microscopically detectable recurrent Plasmodium falciparum parasitemia by day 42 than those receiving other regimens and experienced, on average, a shorter interval before the next clinical episode. Haplotypes of pfcrt and pfmdr1 were also evaluated in persisting parasites. These data identify a possible threat to the parasitological efficacy of artemether-lumefantrine in West Africa, over a decade since it was first introduced on a large scale

New Genetic Insights into Pearl Millet Diversity As Revealed by Characterization of Early- and Late-Flowering Landraces from Senegal

Pearl millet (Pennisetum glaucum (L.) R. Br.) is a staple food and a drought-tolerant cereal well adapted to Sub-Saharan Africa agro-ecosystems. An important diversity of pearl millet landraces has been widely conserved by farmers and therefore could help copping with climate changes and contribute to future food security. Hence, characterizing its genetic diversity and population structure can contribute to better assist breeding programs for a sustainable agricultural productivity enhancement. Toward this goal, a comprehensive panel of 404 accessions were used that correspond to 12 improved varieties, 306 early flowering and 86 late-flowering cultivated landraces from Senegal. Twelve highly polymorphic SSR markers were used to study diversity and population structure. Two genes, PgMADS11 and PgPHYC, were genotyped to assess their association to flowering phenotypic difference in landraces. Results indicate a large diversity and untapped potential of Senegalese pearl millet germplasm as well as a genetic differentiation between early- and late-flowering landraces. Further, a fine-scale genetic difference of PgPHYC and PgMADS11 (SNP and indel, respectively) and co-variation of their alleles with flowering time were found among landraces. These findings highlight new genetic insights of pearl millet useful to define heterotic populations for breeding, genomic association panel, or crosses for trait-specific mapping

Field evaluation of rapid diagnostic tests for meningococcal meningitis in Niger.

International audienceWe confirmed that dipstick RDTs to identify N. meningitidis serogroups A, C, W135 and Y can be reliably operated by non-specialized staff in basic health facilities. RDTs proved very useful to recommend vaccination in NmA epidemics, and also to avoid vaccination in epidemics due to serogroups not included in vaccines (NmX)

Traitement du pied bot varus équin congénital par la méthode de Ponseti

Le pied bot varus équin est l'une des déformations congénitales les plus fréquentes de l'appareil locomoteur. L'objectif de cette étude était de présenter les résultats du traitement des PBVE par la méthode Ponseti sur des patients âgés de 1 à 5 ans. Il s'agissait d'une étude rétrospective, transversale, analytique de septembre 2011 à octobre 2015, portant sur les pieds bots chez les patients âgés de 12 à 60 mois traités par la technique Ponseti. L'âge moyen des patients était de 26 mois avec des extrêmes de 12 à 60 mois. On note 60 garçons pour 18 filles avec un sex-ratio de 3,3. La notion d'hérédité était retrouvée dans 9 cas (11,5%). Le pied bot était bilatéral dans 44 cas (56,4%). Le score moyen de Pirani initial était de 4, 21/6 (1/6 à 5,5/6).Le score final moyen de Pirani était de 1,03/6 (0 à 3,5/6). On note un taux global de 71,8% de succès et un taux de récidive de 12,7%. La technique de Ponseti constitue une alternative crédible dans la prise en charge non chirurgicale du PBVE chez l'enfant, même quand elle est pratiquée tardivement. Talipes equinovarus (TEV) or clubfoot is one of the most common congenital deformities of the musculoskeletal system. The aim of this&nbsp; study was to present the results of Ponseti treatment of TEV in patients aged 1 to 5 years. This was a retrospective, cross-sectional, analytical study from September 2011 to October 2015 of clubfoot in patients aged 12 to 60 months treated with the Ponseti technique. The mean age of the patients was 26 months with extremes of 12 and 60 months. There were 60 boys for 18 girls with a sex ratio of 3.3. The notion of heredity was found in 9 cases (11.5%). Clubfoot was bilateral in 44 cases (56.4%). The mean initial Pirani score was 4.21/6 (1/6 to 5.5/6) and the mean final Pirani score was 1.03/6 (0 to 3.5/6). There was an overall success rate of 71.8% and a recurrence rate of 12.7%. The Ponseti technique is a credible alternative in the non-surgical management of TVE in children, even when used late in life

Ancient Hybridization and Adaptive Introgression of an Invadolysin Gene in Schistosome Parasites

Abstract - Introgression among parasite species has the potential to transfer traits of biomedical importance across species boundaries. The parasitic blood fluke Schistosoma haematobium causes urogenital schistosomiasis in humans across sub-Saharan Africa. Hybridization with other schistosome species is assumed to occur commonly, because genetic crosses between S. haematobium and livestock schistosomes, including S. bovis, can be staged in the laboratory, and sequencing of mtDNA and rDNA amplified from microscopic miracidia larvae frequently reveals markers from different species. However, the frequency, direction, age, and genomic consequences of hybridization are unknown. We hatched miracidia from eggs and sequenced the exomes from 96 individual S. haematobium miracidia from infected patients from Niger and the Zanzibar archipelago. These data revealed no evidence for contemporary hybridization between S. bovis and S. haematobium in our samples. However, all Nigerien S. haematobium genomes sampled show hybrid ancestry, with 3.3–8.2% of their nuclear genomes derived from S. bovis, providing evidence of an ancient introgression event that occurred at least 108–613 generations ago. Some S. bovis-derived alleles have spread to high frequency or reached fixation and show strong signatures of directional selection; the strongest signal spans a single gene in the invadolysin gene family (Chr. 4). Our results suggest that S. bovis/S. haematobium hybridization occurs rarely but demonstrate profound consequences of ancient introgression from a livestock parasite into the genome of S. haematobium, the most prevalent schistosome species infecting humans.© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/ licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. The attached file is the published version of the article.NHM Repositor

Local ancestry to identify selection in response to trypanosome infection in Baoulé x Zebu crossbred cattle in Burkina Faso

The genomes of crossbred (admixed) individuals are a mosaic of ancestral haplotypes formed by recombination in each generation. The proportion of these ancestral haplotypes in certain genomic regions can be responsible for either susceptibility or tolerance against pathogens, and for performances in production traits. Using a medium-density genomic marker panel from the Illumina Bovine SNP50 BeadChip, we estimated individual admixture proportions for Baoulé x Zebu crossbred cattle in Burkina Faso, which were tested for trypanosome infection by direct ELISA from blood samples. Furthermore, we calculated local ancestry deviation from average for each SNP across 29 autosomes to identify potential regions under selection in the trypanotolerant Baoulé cattle and their crossbreds. We identified significant deviation from the local average ancestry (above 5 and 10% genome-wide thresholds) on chromosomes 8 and 19 in the positive animals, while the negative ones showed higher deviation on chromosomes 6, 19, 21, and 22. Some candidate genes on chromosome 6 (PDGFRA) and chromosome 19 (CDC6) have been found associated to trypanotolerance in West African taurines. Screening for FST outliers in trypanosome positive/negative animals we detected seven variants putatively under selection. Finally, we identified a minimum set of highly ancestry informative markers for routine admixture testing. The results of this study contribute to a better understanding of the genetic basis of trypanotolerance in Baoulé cattle and their crossbreeds. Furthermore, we provide a small informative marker set to monitor admixture in this valuable indigenous breed. As such, our results are important for conserving the genetic uniqueness and trypanotolerance of Baoulé cattle, as well as for the improvement of Baoulé and Zebu crossbreds in specific community-based breeding programs