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Maglo KN, Mersha TB, Martin LJ. Population Genomics and the Statistical Values of Race: An Interdisciplinary Perspective on the Biological Classification of Human Populations and Implications for Clinical Genetic Epidemiological Research. Front Genet 2016; 7:22. [PMID: 26925096 PMCID: PMC4756148 DOI: 10.3389/fgene.2016.00022] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 02/02/2016] [Indexed: 01/14/2023] Open
Abstract
The biological status and biomedical significance of the concept of race as applied to humans continue to be contentious issues despite the use of advanced statistical and clustering methods to determine continental ancestry. It is thus imperative for researchers to understand the limitations as well as potential uses of the concept of race in biology and biomedicine. This paper deals with the theoretical assumptions behind cluster analysis in human population genomics. Adopting an interdisciplinary approach, it demonstrates that the hypothesis that attributes the clustering of human populations to "frictional" effects of landform barriers at continental boundaries is empirically incoherent. It then contrasts the scientific status of the "cluster" and "cline" constructs in human population genomics, and shows how cluster may be instrumentally produced. It also shows how statistical values of race vindicate Darwin's argument that race is evolutionarily meaningless. Finally, the paper explains why, due to spatiotemporal parameters, evolutionary forces, and socio-cultural factors influencing population structure, continental ancestry may be pragmatically relevant to global and public health genomics. Overall, this work demonstrates that, from a biological systematic and evolutionary taxonomical perspective, human races/continental groups or clusters have no natural meaning or objective biological reality. In fact, the utility of racial categorizations in research and in clinics can be explained by spatiotemporal parameters, socio-cultural factors, and evolutionary forces affecting disease causation and treatment response.
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Affiliation(s)
- Koffi N Maglo
- Department of Philosophy, Center for Clinical and Translational Science and Training, University of Cincinnati Cincinnati, OH, USA
| | - Tesfaye B Mersha
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati Cincinnati, OH, USA
| | - Lisa J Martin
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati Cincinnati, OH, USA
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252
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Harvey-Leeson S, Karakochuk CD, Hawes M, Tugirimana PL, Bahizire E, Akilimali PZ, Michaux KD, Lynd LD, Whitfield KC, Moursi M, Boy E, Foley J, McLean J, Houghton LA, Gibson RS, Green TJ. Anemia and Micronutrient Status of Women of Childbearing Age and Children 6-59 Months in the Democratic Republic of the Congo. Nutrients 2016; 8:98. [PMID: 26901219 PMCID: PMC4772060 DOI: 10.3390/nu8020098] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/26/2016] [Accepted: 02/05/2016] [Indexed: 01/11/2023] Open
Abstract
Little is known about the micronutrient status of women and children in the Democratic Republic of the Congo, which is critical for the design of effective nutrition interventions. We recruited 744 mother-child pairs from South Kivu (SK) and Kongo Central (KC). We determined hemoglobin (Hb), serum zinc, vitamin B12, folate, ferritin, soluble transferrin receptor (sTfR), retinol binding protein (RBP), C-reactive protein, and α-1 acid glycoprotein concentrations. Anemia prevalence was determined using Hb adjusted for altitude alone and Hb adjusted for both altitude and ethnicity. Anemia prevalence was lower after Hb adjustment for altitude and ethnicity, compared to only altitude, among women (6% vs. 17% in SK; 10% vs. 32% in KC), children 6–23 months (26% vs. 59% in SK; 25% vs. 42% in KC), and children 24–59 months (14% vs. 35% in SK; 23% vs. 44% in KC), respectively. Iron deficiency was seemingly higher with sTfR as compared to inflammation-adjusted ferritin among women (18% vs. 4% in SK; 21% vs. 5% in KC), children 6–23 months (51% vs. 14% in SK; 74% vs. 10% in KC), and children 24–59 months (23% vs. 4% in SK; 58% vs. 1% in KC). Regardless of indicator, iron deficiency anemia (IDA) never exceeded 3% in women. In children, IDA reached almost 20% when sTfR was used but was only 10% with ferritin. Folate, B12, and vitamin A (RBP) deficiencies were all very low (<5%); RBP was 10% in children. The prevalence of anemia was unexpectedly low. Inflammation-adjusted zinc deficiency was high among women (52% in SK; 58% in KC), children 6–23 months (23% in SK; 20% in KC), and children 24–59 months (25% in SK; 27% in KC). The rate of biochemical zinc deficiency among Congolese women and children requires attention.
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Affiliation(s)
- Sarah Harvey-Leeson
- Food, Nutrition and Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Crystal D Karakochuk
- Food, Nutrition and Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Meaghan Hawes
- Food, Nutrition and Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Pierrot L Tugirimana
- Faculty of Medicine, University of Goma, Goma, Democratic Republic of the Congo.
- Department of Clinical Biology, College of Medicine and Heath Science, University of Rwanda, Kigali, Rwanda.
| | - Esto Bahizire
- Faculty of Medicine, Catholic University of Bukavu, Bukavu, Democratic Republic of Congo.
- Center of Research in Natural Sciences of Lwiro, Bukavu, Democratic Republic of the Congo.
| | - Pierre Z Akilimali
- Department of Nutrition, Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of the Congo.
| | - Kristina D Michaux
- Food, Nutrition and Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Larry D Lynd
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Kyly C Whitfield
- Food, Nutrition and Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Mourad Moursi
- International Food Policy Research Institute, Washington, DC 20006, USA.
| | - Erick Boy
- International Food Policy Research Institute, Washington, DC 20006, USA.
| | - Jennifer Foley
- Food, Nutrition and Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Judy McLean
- Food, Nutrition and Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Lisa A Houghton
- Department of Human Nutrition, University of Otago, Dunedin 9016, New Zealand.
| | - Rosalind S Gibson
- Department of Human Nutrition, University of Otago, Dunedin 9016, New Zealand.
| | - Tim J Green
- Food, Nutrition and Health, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
- South Australian Health and Medical Research Institute, and the Women's and Children's Health Research Institute, Adelaide 5000, Australia.
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253
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Akinyemi RO, Ovbiagele B, Akpalu A, Jenkins C, Sagoe K, Owolabi L, Sarfo F, Obiako R, Gebreziabher M, Melikam E, Warth S, Arulogun O, Lackland D, Ogunniyi A, Tiwari H, Kalaria RN, Arnett D, Owolabi MO. Stroke genomics in people of African ancestry: charting new paths. Cardiovasc J Afr 2016; 26:S39-49. [PMID: 25962947 PMCID: PMC4557488 DOI: 10.5830/cvja-2015-039] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
One in six people worldwide will experience a stroke in his/her lifetime. While people in Africa carry a disproportionately higher burden of poor stroke outcomes, compared to the rest of the world, the exact contribution of genomic factors to this disparity is unknown. Despite noteworthy research into stroke genomics, studies exploring the genetic contribution to stroke among populations of African ancestry in the United States are few. Furthermore, genomics data in populations living in Africa are lacking. The wide genomic variation of African populations offers a unique opportunity to identify genomic variants with causal relationships to stroke across different ethnic groups. The Stroke Investigative Research and Educational Network (SIREN), a component of the Human Health and Heredity in Africa (H3Africa) Consortium, aims to explore genomic and environmental risk factors for stroke in populations of African ancestry in West Africa and the United States. In this article, we review the literature on the genomics of stroke with particular emphasis on populations of African origin.
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Affiliation(s)
- R O Akinyemi
- Division of Neurology, Federal Medical Centre Abeokuta, Nigeria; Institute of Neuroscience, Newcastle University, UK
| | - B Ovbiagele
- Department of Neurosciences, Medical University of South Carolina, USA
| | - A Akpalu
- College of Health Sciences, University of Ghana, Accra, Ghana
| | | | - K Sagoe
- College of Health Sciences, University of Ghana, Accra, Ghana
| | - L Owolabi
- Department of Medicine, Bayero University, Kano, Nigeria
| | - F Sarfo
- School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - R Obiako
- Department of Medicine, Ahmadu Bello University, Zaria, Nigeria
| | - M Gebreziabher
- Department of Neurosciences, Medical University of South Carolina, USA
| | - E Melikam
- College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - S Warth
- Department of Neurosciences, Medical University of South Carolina, USA
| | - O Arulogun
- College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - D Lackland
- Department of Neurosciences, Medical University of South Carolina, USA
| | - A Ogunniyi
- College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - H Tiwari
- Department of Public Health, University of Alabama at Birmingham, USA
| | - R N Kalaria
- Institute of Neuroscience, Newcastle University, UK
| | - D Arnett
- Department of Public Health, University of Alabama at Birmingham, USA
| | - M O Owolabi
- College of Medicine, University of Ibadan, Ibadan, Nigeria
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254
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Owusu EDA, Buabeng V, Dadzie S, Brown CA, Grobusch MP, Mens P. Characteristics of asymptomatic Plasmodium spp. parasitaemia in Kwahu-Mpraeso, a malaria endemic mountainous district in Ghana, West Africa. Malar J 2016; 15:38. [PMID: 26801407 PMCID: PMC4724116 DOI: 10.1186/s12936-015-1066-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 12/22/2015] [Indexed: 12/01/2022] Open
Abstract
Background Malaria control efforts in Ghana have reduced the countrywide average malaria prevalence from 71 % in 2000 to about 51 % in 2012; however, its main focus is on symptomatic malaria. If further progress is to be made, parasite
reservoirs in asymptomatic carriers need to be moved into focus. This study profiles asymptomatic Plasmodium spp. parasitaemia amongst residents of mountainous Kwahu-Mpraeso in the Eastern region of Ghana. Methods A cross-sectional study of 360 residents was carried out from October to December 2013. This included recording demographics, malaria testing of asymptomatic residents, and gathering of their malaria history. Assessment of malaria transmission was done with molecular identification of vectors, determination of sporozoite rate, insecticide resistance status and biting pattern. Univariate and multivariate analysis were used to establish risk determinants. Results In Mpraeso, in the Kwahu highland of Eastern Region, children were at higher risk of asymptomatic parasitaemia, thereby contributing to the parasite reservoir and hence sustained malaria transmission. As well, findings suggested Hb AC genotype influenced susceptibility to asymptomatic malaria with 8.03-fold increase in odds (univariate) and 11.92-fold higher odds (multivariate) than the normal Hb AA. The mosquito vector predominant in the area was Anopheles gambiae sensu stricto of the homozygous pyrethroid resistant form (RR); with biting mainly occurring indoors. Conclusion For an effective malaria control in this area, interventions should be formulated and implemented to target asymptomatic parasite reservoirs; especially in children and people with Hb AC. The dominant vector species An. gambiae s.s. and its feeding patterns of biting indoors should also be considered.
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Affiliation(s)
- Ewurama D A Owusu
- Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Centre, Centre of Tropical Medicine and Travel Medicine, University of Amsterdam, Amsterdam, The Netherlands. .,Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra, Ghana. .,Department of Parasitology, KIT Biomedical Research Institute, Amsterdam, The Netherlands.
| | - Vincent Buabeng
- Medical Laboratory Department, Atibie Government Hospital, Kwahu-Atibie, Ghana.
| | - Samuel Dadzie
- Medical Entomology Unit, Department of Parasitology, Noguchi Memorial Institute of Medical Research, University of Ghana, Accra, Ghana.
| | - Charles A Brown
- Department of Medical Laboratory Sciences, School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Accra, Ghana.
| | - Martin P Grobusch
- Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Centre, Centre of Tropical Medicine and Travel Medicine, University of Amsterdam, Amsterdam, The Netherlands. .,Centre de Recherches Médicales de Lambaréné (CERMEL), Hôpital Albert Schweitzer, Lambaréné, Gabon. .,Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.
| | - Petra Mens
- Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Centre, Centre of Tropical Medicine and Travel Medicine, University of Amsterdam, Amsterdam, The Netherlands. .,Department of Parasitology, KIT Biomedical Research Institute, Amsterdam, The Netherlands.
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255
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Gonçalves BP, Gupta S, Penman BS. Sickle haemoglobin, haemoglobin C and malaria mortality feedbacks. Malar J 2016; 15:26. [PMID: 26753833 PMCID: PMC4709991 DOI: 10.1186/s12936-015-1077-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 12/29/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sickle haemoglobin (HbS) and haemoglobin C (HbC) are both caused by point mutations in the beta globin gene, and both offer substantial malaria protection. Despite the fact that the blood disorder caused by homozygosity for HbC is much less severe than that caused by homozygosity for HbS (sickle cell anaemia), it is the sickle mutation which has come to dominate many old-world malarious regions, whilst HbC is highly restricted in its geographical distribution. It has been suggested that this discrepancy may be due to sickle cell heterozygotes enjoying a higher level of malaria protection than heterozygotes for HbC. A higher fitness of sickle cell heterozygotes relative to HbC heterozygotes could certainly have allowed the sickle cell allele to spread more rapidly. However, observations that carrying either HbC or HbS enhances an individual's capacity to transmit malaria parasites to mosquitoes could also shed light on this conundrum. METHODS A population genetic model was used to investigate the evolutionary consequences of the strength of malaria selection being correlated with either HbS frequency or HbC frequency. RESULTS If the selection pressure from malaria is positively correlated with the frequency of either HbS or HbC, it is easier for HbS to succeed in the competitive interaction between the two alleles. CONCLUSIONS A feedback process whereby the presence of variant haemoglobins increases the level of malaria selection in a population could have contributed to the global success of HbS relative to HbC, despite the former's higher blood disorder cost.
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Affiliation(s)
- Bronner P Gonçalves
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, W1CE 7HT, UK.
| | - Sunetra Gupta
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK.
| | - Bridget S Penman
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK.
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256
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Abstract
With increasing malaria control and goals of malaria elimination, many endemic areas are transitioning from high-to-low-to-no malaria transmission. Reductions in transmission will impact on the development of naturally acquired immunity to malaria, which develops after repeated exposure to Plasmodium spp. However, it is currently unclear how declining transmission and malaria exposure will affect the development and maintenance of naturally acquired immunity. Here we review the key processes which underpin this knowledge; the amount of Plasmodium spp. exposure required to generate effective immune responses, the longevity of antibody responses and the ability to mount an effective response upon re-exposure through memory responses. Lastly we identify research priorities which will increase our understanding of how changing transmission will impact on malarial immunity.
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257
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Piel FB, Adamkiewicz TV, Amendah D, Williams TN, Gupta S, Grosse SD. Observed and expected frequencies of structural hemoglobin variants in newborn screening surveys in Africa and the Middle East: deviations from Hardy-Weinberg equilibrium. Genet Med 2015; 18:265-74. [PMID: 26633548 DOI: 10.1038/gim.2015.143] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/25/2015] [Indexed: 02/07/2023] Open
Abstract
PURPOSE Our objective was to compare observed and expected genotype proportions from newborn screening surveys of structural hemoglobin variants. METHODS We conducted a systematic review of newborn screening surveys of hemoglobins S and C in Africa and the Middle East. We compared observed frequencies to those expected assuming Hardy-Weinberg equilibrium (HWE). Significant deviations were identified by an exact test. The fixation index FIS was calculated to assess excess homozygosity. We compared newborn estimates corrected and uncorrected for HWE deviations using demographic data. RESULTS Sixty samples reported genotype counts for hemoglobin variants in Africa and the Middle East. Observed and expected counts matched in 27%. The observed number of sickle cell anemia (SCA) individuals was higher than expected in 42 samples, reaching significance (P < 0.05) in 24. High FIS values were common across the study regions. The estimated total number of newborns with SCA, corrected based on FIS, was 33,261 annual births instead of 24,958 for the 38 samples across sub-Saharan Africa and 1,109 annual births instead of 578 for 12 samples from the Middle East. CONCLUSION Differences between observed and expected genotype frequencies are common in surveys of hemoglobin variants in the study regions. Further research is required to identify and quantify factors responsible for such deviations. Estimates based on HWE might substantially underestimate the annual number of SCA-affected newborns (up to one-third in sub-Saharan Africa and one-half in the Middle East).
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Affiliation(s)
| | - Thomas V Adamkiewicz
- Department of Family Medicine, Morehouse School of Medicine, Atlanta, Georgia, USA
| | - Djesika Amendah
- African Population and Health Research Center, Nairobi, Kenya
| | - Thomas N Williams
- Kenya Medical Research Institute-Wellcome Trust Programme, Centre for Geographic Medicine Research-Coast, Kilifi District Hospital, Kilifi, Kenya.,Department of Medicine, Imperial College, St Mary's Hospital, London, UK
| | - Sunetra Gupta
- Department of Zoology, University of Oxford, Oxford, UK
| | - Scott D Grosse
- National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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258
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Hockham C, Piel FB, Gupta S, Penman BS. Understanding the contrasting spatial haplotype patterns of malaria-protective β-globin polymorphisms. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2015; 36:174-183. [PMID: 26394108 PMCID: PMC4653953 DOI: 10.1016/j.meegid.2015.09.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/04/2015] [Accepted: 09/06/2015] [Indexed: 12/24/2022]
Abstract
The malaria-protective β-globin polymorphisms, sickle-cell (β(S)) and β(0)-thalassaemia, are canonical examples of human adaptation to infectious disease. Occurring on distinct genetic backgrounds, they vary markedly in their patterns of linked genetic variation at the population level, suggesting different evolutionary histories. β(S) is associated with five classical restriction fragment length polymorphism haplotypes that exhibit remarkable specificity in their geographical distributions; by contrast, β(0)-thalassaemia mutations are found on haplotypes whose distributions overlap considerably. Here, we explore why these two polymorphisms display contrasting spatial haplotypic distributions, despite having malaria as a common selective pressure. We present a meta-population genetic model, incorporating individual-based processes, which tracks the evolution of β-globin polymorphisms on different haplotypic backgrounds. Our simulations reveal that, depending on the rate of mutation, a large population size and/or high population growth rate are required for both the β(S)- and the β(0)-thalassaemia-like patterns. However, whilst the β(S)-like pattern is more likely when population subdivision is high, migration low and long-distance migration absent, the opposite is true for β(0)-thalassaemia. Including gene conversion has little effect on the overall probability of each pattern; however, when inter-haplotype fitness variation exists, gene conversion is more likely to have contributed to the diversity of haplotypes actually present in the population. Our findings highlight how the contrasting spatial haplotype patterns exhibited by β(S) and β(0)-thalassaemia may provide important indications as to the evolution of these adaptive alleles and the demographic history of the populations in which they have evolved.
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Affiliation(s)
| | | | - Sunetra Gupta
- Department of Zoology, University of Oxford, Oxford, UK.
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259
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Nguyen VT, Nassar D, Batteux F, Raymond K, Tharaux PL, Aractingi S. Delayed Healing of Sickle Cell Ulcers Is due to Impaired Angiogenesis and CXCL12 Secretion in Skin Wounds. J Invest Dermatol 2015; 136:497-506. [PMID: 26967481 DOI: 10.1016/j.jid.2015.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 08/14/2015] [Accepted: 10/12/2015] [Indexed: 01/31/2023]
Abstract
Leg ulcers are a major complication of sickle cell disease that occur in 2.5-40% of patients. Leg ulcers are responsible for frequent complications because they are often long-lasting and are highly resistant to therapy. Although their occurrence is associated with hyperhemolysis, the mechanisms underlying sickle cell ulcers remain poorly understood. In this study, we show that skin wound healing is severely altered in old SAD sickle cell mice but is normal in young animals, consistent with reports in humans. Alterations of wound healing were associated with impaired blood and lymphatic angiogenesis in the wound beds and poor endothelial progenitor cell mobilization from the bone marrow. CXCL12 secretion by keratinocytes and inflammatory cells was low in the wounds of SAD mice. Local therapy with endothelial progenitor cells or recombinant CXCL12 injections restored wound angiogenesis and rescued the healing defect together with mobilization of circulating endothelial progenitor cells. To our knowledge, this is a previously unreported study of the cellular and molecular mechanisms of sickle cell ulcers in a murine model that provides promising therapeutic perspectives for clinical trials.
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Affiliation(s)
- Van Tuan Nguyen
- Progenitors and Endothelial Cells During and After Pregnancy Laboratory, INSERM UMR_S 938, Centre de Recherche, St. Antoine, Paris, France; UPMC-Université Paris 6, Paris, France
| | - Dany Nassar
- Progenitors and Endothelial Cells During and After Pregnancy Laboratory, INSERM UMR_S 938, Centre de Recherche, St. Antoine, Paris, France; UPMC-Université Paris 6, Paris, France; Department of Dermatology, American University of Beirut Medical Centre, Beirut, Lebanon; Department of Anatomy, Cell Biology and Physiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Fréderic Batteux
- Faculty of Medicine, Université Paris Descartes-Paris 5, Paris, France
| | - Karine Raymond
- Progenitors and Endothelial Cells During and After Pregnancy Laboratory, INSERM UMR_S 938, Centre de Recherche, St. Antoine, Paris, France
| | | | - Sélim Aractingi
- Progenitors and Endothelial Cells During and After Pregnancy Laboratory, INSERM UMR_S 938, Centre de Recherche, St. Antoine, Paris, France; Faculty of Medicine, Université Paris Descartes-Paris 5, Paris, France; Department of Dermatology, Hôpital Cochin-Tarnier, Paris, France.
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260
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Asplund CA, O'Connor FG. Challenging Return to Play Decisions: Heat Stroke, Exertional Rhabdomyolysis, and Exertional Collapse Associated With Sickle Cell Trait. Sports Health 2015; 8:117-25. [PMID: 26896216 PMCID: PMC4789928 DOI: 10.1177/1941738115617453] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Context: Sports medicine providers frequently return athletes to play after sports-related injuries and conditions. Many of these conditions have guidelines or medical evidence to guide the decision-making process. Occasionally, however, sports medicine providers are challenged with complex medical conditions for which there is little evidence-based guidance and physicians are instructed to individualize treatment; included in this group of conditions are exertional heat stroke (EHS), exertional rhabdomyolysis (ER), and exertional collapse associated with sickle cell trait (ECAST). Evidence Acquisition: The MEDLINE (2000-2015) database was searched using the following search terms: exertional heat stroke, exertional rhabdomyolysis, and exertional collapse associated with sickle cell trait. References from consensus statements, review articles, and book chapters were also utilized. Study Design: Clinical review. Level of Evidence: Level 4. Results: These entities are unique in that they may cause organ system damage capable of leading to short- or long-term detriments to physical activity and may not lend to complete recovery, potentially putting the athlete at risk with premature return to play. Conclusion: With a better understanding of the pathophysiology of EHS, ER, and ECAST and the factors associated with recovery, better decisions regarding return to play may be made.
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Affiliation(s)
- Chad A Asplund
- Athletic Medicine, Division of Health Services, Health and Kinesiology, Georgia Southern University, Statesboro, Georgia
| | - Francis G O'Connor
- Military and Emergency Medicine, Consortium for Health and Military Performance, Uniformed Services University of the Health Sciences, Bethesda, Maryland
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261
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Edge MD, Rosenberg NA. A General Model of the Relationship between the Apportionment of Human Genetic Diversity and the Apportionment of Human Phenotypic Diversity. Hum Biol 2015; 87:313-337. [PMID: 27737590 PMCID: PMC8504698 DOI: 10.13110/humanbiology.87.4.0313] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Models that examine genetic differences between populations alongside a genotype-phenotype map can provide insight about phenotypic variation among groups. We generalize a simple model of a completely heritable, additive, selectively neutral quantitative trait to examine the relationship between single-locus genetic differentiation and phenotypic differentiation on quantitative traits. In agreement with similar efforts using different models, we show that the expected degree to which two groups differ on a neutral quantitative trait is not strongly affected by the number of genetic loci that influence the trait: neutral trait differences are expected to have a magnitude comparable to the genetic differences at a single neutral locus. We discuss this result with respect to population differences in disease phenotypes, arguing that although neutral genetic differences between populations can contribute to specific differences between populations in health outcomes, systematic patterns of difference that run in the same direction for many genetically independent health conditions are unlikely to be explained by neutral genetic differentiation.
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Affiliation(s)
- Michael D. Edge
- Department of Biology, Stanford University, Stanford, California
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262
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Williams TN. An accurate and affordable test for the rapid diagnosis of sickle cell disease could revolutionize the outlook for affected children born in resource-limited settings. BMC Med 2015; 13:238. [PMID: 26399886 PMCID: PMC4580219 DOI: 10.1186/s12916-015-0483-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 09/08/2015] [Indexed: 12/16/2022] Open
Abstract
Each year, at least 280,000 children are born with sickle cell disease (SCD) in resource-limited settings. For cost, logistic and political reasons, the availability of SCD testing is limited in such settings and consequently 50-90 % of affected children die undiagnosed before their fifth birthday. The recent development of a point of care method for the diagnosis of SCD - the Sickle SCAN™ device - could afford such children the prompt access to appropriate services that has transformed the outlook for affected children in resource-rich areas. In research published in BMC Medicine, Kanter and colleagues describe a small but carefully conducted study involving 208 children and adults, in which they found that by using Sickle SCAN™ it was possible to diagnose the common forms of SCD with 99 % sensitivity and 99 % specificity, in under 5 minutes. If repeatable both in newborn babies and under real-life conditions, and if marketed at an affordable price, Sickle SCAN™ could revolutionize the survival prospects for children born with SCD in resource-limited areas.Please see related article: http://dx.doi.org/10.1186/s12916-015-0473-6.
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Affiliation(s)
- Thomas N Williams
- Department of Medicine, Imperial College, St Mary's Hospital, London, W2 1NY, UK. .,KEMRI/Wellcome Trust Research Programme, PO Box 230, Kilifi, Kenya.
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Tewari S, Brousse V, Piel FB, Menzel S, Rees DC. Environmental determinants of severity in sickle cell disease. Haematologica 2015; 100:1108-16. [PMID: 26341524 PMCID: PMC4800688 DOI: 10.3324/haematol.2014.120030] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/05/2015] [Indexed: 12/13/2022] Open
Abstract
Sickle cell disease causes acute and chronic illness, and median life expectancy is reduced by at least 30 years in all countries, with greater reductions in low-income countries. There is a wide spectrum of severity, with some patients having no symptoms and others suffering frequent, life-changing complications. Much of this variability is unexplained, despite increasingly sophisticated genetic studies. Environmental factors, including climate, air quality, socio-economics, exercise and infection, are likely to be important, as demonstrated by the stark differences in outcomes between patients in Africa and USA/Europe. The effects of weather vary with geography, although most studies show that exposure to cold or wind increases hospital attendance with acute pain. Most of the different air pollutants are closely intercorrelated, and increasing overall levels seem to correlate with increased hospital attendance, although higher concentrations of atmospheric carbon monoxide may offer some benefit for patients with sickle cell disease. Exercise causes some adverse physiological changes, although this may be off-set by improvements in cardiovascular health. Most sickle cell disease patients live in low-income countries and socioeconomic factors are undoubtedly important, but little studied beyond documenting that sickle cell disease is associated with decreases in some measures of social status. Infections cause many of the differences in outcomes seen across the world, but again these effects are relatively poorly understood. All the above factors are likely to account for much of the pathology and variability of sickle cell disease, and large prospective studies are needed to understand these effects better.
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Affiliation(s)
- Sanjay Tewari
- Department of Molecular Haematology, King's College London School of Medicine, King's College Hospital, London, England
| | - Valentine Brousse
- Reference Centre for Sickle Cell Disease, Pediatric Department, Hôpital Universitaire Necker-Enfants Malades, APHP, Paris; Université Paris Descartes, France
| | | | - Stephan Menzel
- Department of Molecular Haematology, King's College London School of Medicine, King's College Hospital, London, England
| | - David C Rees
- Department of Molecular Haematology, King's College London School of Medicine, King's College Hospital, London, England
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264
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Karki R, Pandya D, Elston RC, Ferlini C. Defining "mutation" and "polymorphism" in the era of personal genomics. BMC Med Genomics 2015; 8:37. [PMID: 26173390 PMCID: PMC4502642 DOI: 10.1186/s12920-015-0115-z] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 07/06/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The growing advances in DNA sequencing tools have made analyzing the human genome cheaper and faster. While such analyses are intended to identify complex variants, related to disease susceptibility and efficacy of drug responses, they have blurred the definitions of mutation and polymorphism. DISCUSSION In the era of personal genomics, it is critical to establish clear guidelines regarding the use of a reference genome. Nowadays DNA variants are called as differences in comparison to a reference. In a sequencing project Single Nucleotide Polymorphisms (SNPs) and DNA mutations are defined as DNA variants detectable in >1 % or <1 % of the population, respectively. The alternative use of the two terms mutation or polymorphism for the same event (a difference as compared with a reference) can lead to problems of classification. These problems can impact the accuracy of the interpretation and the functional relationship between a disease state and a genomic sequence. We propose to solve this nomenclature dilemma by defining mutations as DNA variants obtained in a paired sequencing project including the germline DNA of the same individual as a reference. Moreover, the term mutation should be accompanied by a qualifying prefix indicating whether the mutation occurs only in somatic cells (somatic mutation) or also in the germline (germline mutation). We believe this distinction in definition will help avoid confusion among researchers and support the practice of sequencing the germline and somatic tissues in parallel to classify the DNA variants thus defined as mutations.
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Affiliation(s)
- Roshan Karki
- Danbury Hospital Research Institute, Western Connecticut Health Network, 131 West Street, Danbury, CT, 06810, USA
| | - Deep Pandya
- Danbury Hospital Research Institute, Western Connecticut Health Network, 131 West Street, Danbury, CT, 06810, USA
| | - Robert C Elston
- Department of Epidemiology and Biostatistics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Cristiano Ferlini
- Danbury Hospital Research Institute, Western Connecticut Health Network, 131 West Street, Danbury, CT, 06810, USA.
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265
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Abstract
Sickle cell disease (SCD) is a genetic disorder that poses a serious health threat in tropical Africa, which the World Health Organization has declared a public health priority. Its persistence in human populations has been attributed to the resistance it provides to Plasmodium falciparum malaria in its heterozygous state, called sickle cell trait (SCT). Because of migration, SCT is becoming common outside tropical countries: It is now the most important genetic disorder in France, affecting one birth for every 2,400, and one of the most common in the United States. We assess the strength of the association between SCT and malaria, using current data for both SCT and malaria infections. A total of 3,959 blood samples from 195 villages distributed over the entire Republic of Gabon were analyzed. Hemoglobin variants were identified by using HPLCy (HPLC). Infections by three species of Plasmodium were detected by PCR followed by sequencing of a 201-bp fragment of cytochrome b. An increase of 10% in P. falciparum malaria prevalence is associated with an increase by 4.3% of SCT carriers. An increase of 10 y of age is associated with an increase by 5.5% of SCT carriers. Sex is not associated with SCT. These strong associations show that malaria remains a selective factor in current human populations, despite the progress of medicine and the actions undertaken to fight this disease. Our results provide evidence that evolution is still present in humans, although this is sometimes questioned by scientific, political, or religious personalities.
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266
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Kaufman JS, Dolman L, Rushani D, Cooper RS. The contribution of genomic research to explaining racial disparities in cardiovascular disease: a systematic review. Am J Epidemiol 2015; 181:464-72. [PMID: 25731887 DOI: 10.1093/aje/kwu319] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
After nearly a decade of genome-wide association studies, no assessment has yet been made of their contribution toward an explanation of the most prominent racial health disparities observed at the population level. We examined populations of African and European ancestry and focused on cardiovascular diseases, which are collectively the largest contributor to the racial mortality gap. We conducted a systematic search for review articles and meta-analyses published in 2007-2013 in which genetic data from both populations were available. We identified 68 articles relevant to this question; however, few reported significant associations in both racial groups, with just 3 variants meeting study-specific significance criteria. For most outcomes, there were too few estimates for quantitative summarization, but when summarization was possible, racial group did not contribute to heterogeneity. Most associations reported from genome-wide searches were small, difficult to replicate, and in no consistent direction that favored one racial group or another. Although the substantial investment in this technology might have produced clinical advances, it has thus far made little or no contribution to our understanding of population-level racial health disparities in cardiovascular disease.
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267
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Nyström S, Hammarström P. Is the prevalent human prion protein 129M/V mutation a living fossil from a Paleolithic panzootic superprion pandemic? Prion 2015; 8:2-10. [PMID: 24398570 PMCID: PMC7030913 DOI: 10.4161/pri.27601] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Prion diseases are consistently associated with prion protein (PrP(C)) misfolding rendering a cascade of auto-catalytic self-perpetuation of misfolded PrP in an afflicted individual. The molecular process is intriguingly similar to all known amyloid diseases both local and systemic. The prion disease is also infectious by the transfer of misfolded PrP from one individual to the next. Transmissibility is surprisingly efficient in prion diseases and given the rapid disease progression following initial symptoms the prionoses stand out from other amyloidoses, which all may be transmissible under certain circumstances. The nature of the infectious prion as well as the genotype of the host is important for transmissibility. For hitherto unexplained reasons the majority of Europeans carry a missense mutation on one or both alleles of the PrP gene (PRNP), and hence express a variant of PrP with a substitution for valine (V) instead of methionine (M) in position 129. In fact the 129M/V variant is very common in all populations except for the Japanese. Sporadic Creutzfeldt-Jakob disease is a disease rarely striking people below the age of 60, where homozygosity especially 129MM is a very strong risk factor. Paradoxically, the 129M/V polymorphism suggestive of heterozygote advantage is one of the most clear cut disease associated traits of the human population, yet prion disease is extraordinarily rare. The genetic basis for how this trait spread with such prevalence within human populations is still target to investigations and deserves attention. This short essay represents a somewhat provocative hypothetical notion of a possible ancient significance of this polymorphism.
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268
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Kilian N, Srismith S, Dittmer M, Ouermi D, Bisseye C, Simpore J, Cyrklaff M, Sanchez CP, Lanzer M. Hemoglobin S and C affect protein export in Plasmodium falciparum-infected erythrocytes. Biol Open 2015; 4:400-10. [PMID: 25701664 PMCID: PMC4359745 DOI: 10.1242/bio.201410942] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Malaria is a potentially deadly disease. However, not every infected person develops severe symptoms. Some people are protected by naturally occurring mechanisms that frequently involve inheritable modifications in their hemoglobin. The best studied protective hemoglobins are the sickle cell hemoglobin (HbS) and hemoglobin C (HbC) which both result from a single amino acid substitution in β-globin: glutamic acid at position 6 is replaced by valine or lysine, respectively. How these hemoglobinopathies protect from severe malaria is only partly understood. Models currently proposed in the literature include reduced disease-mediating cytoadherence of parasitized hemoglobinopathic erythrocytes, impaired intraerythrocytic development of the parasite, dampened inflammatory responses, or a combination thereof. Using a conditional protein export system and tightly synchronized Plasmodium falciparum cultures, we now show that export of parasite-encoded proteins across the parasitophorous vacuolar membrane is delayed, slower, and reduced in amount in hemoglobinopathic erythrocytes as compared to parasitized wild type red blood cells. Impaired protein export affects proteins targeted to the host cell cytoplasm, Maurer's clefts, and the host cell plasma membrane. Impaired protein export into the host cell compartment provides a mechanistic explanation for the reduced cytoadherence phenotype associated with parasitized hemoglobinopathic erythrocytes.
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Affiliation(s)
- Nicole Kilian
- Center of Infectious Diseases, Parasitology, Heidelberg University, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Sirikamol Srismith
- Center of Infectious Diseases, Parasitology, Heidelberg University, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Martin Dittmer
- Center of Infectious Diseases, Parasitology, Heidelberg University, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Djeneba Ouermi
- Biomolecular Research Center Pietro Annigoni, University of Ouagadougou, 01 BP 364 Ouagadougou, Burkina Faso
| | - Cyrille Bisseye
- Biomolecular Research Center Pietro Annigoni, University of Ouagadougou, 01 BP 364 Ouagadougou, Burkina Faso
| | - Jacques Simpore
- Biomolecular Research Center Pietro Annigoni, University of Ouagadougou, 01 BP 364 Ouagadougou, Burkina Faso
| | - Marek Cyrklaff
- Center of Infectious Diseases, Parasitology, Heidelberg University, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Cecilia P Sanchez
- Center of Infectious Diseases, Parasitology, Heidelberg University, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Michael Lanzer
- Center of Infectious Diseases, Parasitology, Heidelberg University, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
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269
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Ngwira A, Kazembe LN. Bayesian random effects modelling with application to childhood anaemia in Malawi. BMC Public Health 2015; 15:161. [PMID: 25885648 PMCID: PMC4358301 DOI: 10.1186/s12889-015-1494-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 01/07/2015] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Epidemiological studies in Malawi on child anaemia have neglected the community spatial effect to childhood anaemia. Neglecting the community spatial effect in the model ignores the influence of unobserved or unmeasured contextual variables, and at the same time the resultant model may under estimate model parameter standard errors which can result in erroneous significance of covariates. We aimed at investigating risk factors of childhood anaemia in Malawi with focus on geographical spatial effect. METHODS We adopted a Bayesian random effect model for child anaemia with district as spatial effect using the 2010 Malawi demographic healthy survey data. We fitted the binary logistic model for the two categories outcome (anaemia (Hb < 11), and no anaemia (Hb ≥ 11)). Continuous covariates were modelled by the penalized splines and spatial effects were smoothed by the two dimensional spline. RESULTS Residual spatial patterns reveal Nsanje, Chikhwawa, Salima, Nkhota-kota, Mangochi and Machinga increasing the risk of childhood anaemia. Karonga, Chitipa, Rumphi, Mzimba, Ntchisi, and Chiradzulu reduce the risk of childhood anaemia. Known determinants such as maternal anaemia, child stunting, and child fever, have a positive effect on child anaemia. Furthermore childhood anaemia decreases with child age. It also decreases with wealth index. There is a U relationship between child anaemia and mother age. CONCLUSION Strategies in childhood anaemia control should be tailored to local conditions, taking into account the specific etiology and prevalence of anaemia.
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Affiliation(s)
- Alfred Ngwira
- Department of Mathematical Sciences, University of Malawi, Chancellor College, Zomba, Malawi.
| | - Lawrence N Kazembe
- Department of Statistics and Population Studies, University of Namibia, Windhoek, Namibia.
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270
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Abstract
Sickle cell disease (SCD) is a single gene disorder causing a debilitating systemic syndrome characterised by chronic anaemia, acute painful episodes, organ infarction and chronic organ damage and by a significant reduction in life expectancy. The origin of SCD lies in the malarial regions of the tropics where carriers are protected against death from malaria and hence enjoy an evolutionary advantage. More recently, population migration has meant that SCD now has a worldwide distribution and that a substantial number of children are born with the condition in higher-income areas, including large parts of Europe and North and South America. Newborn screening, systematic clinical follow-up and prevention of sepsis and organ damage have led to an increased life expectancy among people with SCD in many such countries; however, in resource-limited settings where the majority continue to be born, most affected children continue to die in early childhood, usually undiagnosed, due to the lack of effective programmes for its early detection and treatment. As new therapies emerge, potentially leading to disease amelioration or cure, it is of paramount importance that the significant burden of SCD in resource-poor countries is properly recognised.
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Affiliation(s)
| | - Thomas N Williams
- Department of Medicine, Imperial College, London, UK,KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
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271
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Mulumba LL, Wilson L. Sickle cell disease among children in Africa: An integrative literature review and global recommendations. INTERNATIONAL JOURNAL OF AFRICA NURSING SCIENCES 2015. [DOI: 10.1016/j.ijans.2015.08.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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272
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Kerner B. Toward a Deeper Understanding of the Genetics of Bipolar Disorder. Front Psychiatry 2015; 6:105. [PMID: 26283973 PMCID: PMC4522874 DOI: 10.3389/fpsyt.2015.00105] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 07/08/2015] [Indexed: 12/15/2022] Open
Abstract
Bipolar disorder is a common, complex psychiatric disorder characterized by mania and depression. The disease aggregates in families, but despite much effort, it has been difficult to delineate the basic genetic model or identify specific genetic risk factors. Not only single gene Mendelian transmission and common variant hypotheses but also multivariate threshold models and oligogenic quasi-Mendelian modes of inheritance have dominated the discussion at times. Almost complete sequence information of the human genome and falling sequencing costs now offer the opportunity to test these models in families in which the disorder is transmitted over several generations. Exome-wide sequencing studies have revealed an astonishing number of rare and potentially damaging mutations in brain-expressed genes that could have contributed to the disease manifestation. However, the statistical analysis of these data has been challenging, because genetic risk factors displayed a high degree of dissimilarity across families. This scenario is not unique to bipolar disorder, but similar results have also been found in schizophrenia, a potentially related psychiatric disorder. Recently, our group has published data which supported an oligogenic genetic model of transmission in a family with bipolar disorder. In this family, three affected siblings shared rare, damaging mutations in multiple genes, which were linked to stress response pathways. These pathways are also the target for drugs frequently used to treat bipolar disorder. This article discusses these findings in the context of previously proclaimed disease models and suggests future research directions, including biological confirmation and phenotype stratification as an approach to disease heterogeneity.
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Affiliation(s)
- Berit Kerner
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles , Los Angeles, CA , USA
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273
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Mwakasungula S, Schindler T, Jongo S, Moreno E, Kamaka K, Mohammed M, Joseph S, Rashid R, Athuman T, Tumbo AM, Hamad A, Lweno O, Tanner M, Shekalaghe S, Daubenberger CA. Red blood cell indices and prevalence of hemoglobinopathies and glucose 6 phosphate dehydrogenase deficiencies in male Tanzanian residents of Dar es Salaam. INTERNATIONAL JOURNAL OF MOLECULAR EPIDEMIOLOGY AND GENETICS 2014; 5:185-194. [PMID: 25755846 PMCID: PMC4348704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 11/12/2014] [Indexed: 06/04/2023]
Abstract
Hemoglobinopathies, disorders of hemoglobin structure and production, are one of the most common monogenic disorders in humans. Glucose 6 phosphate dehydrogenase deficiency (G6PD) is an inherited enzymopathy resulting in increased oxygen stress susceptibility of red blood cells. The distributions of these genetic traits in populations living in tropical and subtropical regions where malaria has been or is still present are thought to result from survival advantage against severe life threatening malaria disease. 384 male Tanzanian volunteers residing in Dar es Salaam were typed for G6PD, sickle cell disease and α-thalassemia. The most prominent red blood cell polymorphism was heterozygous α(+)-thalassemia (37.8%), followed by the G6PD(A) deficiency (16.4%), heterozygous sickle cell trait (15.9%), G6PD(A-) deficiency (13.5%) and homozygous α(+)-thalassemia (5.2%). 35%, 45%, 17% and 3% of these volunteers were carriers of wild type gene loci, one, two or three of these hemoglobinopathies, respectively. We find that using a cut off value of 28.6 pg. for mean corpuscular hemoglobin (MCH), heterozygous α(+)-thalassemia can be predicted with a sensitivity of 84% and specificity of 72% in this male population. All subjects carrying homozygous α(+)-thalassemia were identified based on their MCH value < 28.6 pg.
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Affiliation(s)
- Solomon Mwakasungula
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health InstituteSocinstrasse 57, 4002 Basel, Switzerland
- University of BaselBasel, Petersplatz 1, CH-4003 Basel, Switzerland
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Tobias Schindler
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health InstituteSocinstrasse 57, 4002 Basel, Switzerland
- University of BaselBasel, Petersplatz 1, CH-4003 Basel, Switzerland
| | - Said Jongo
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Elena Moreno
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Kasimu Kamaka
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Mgeni Mohammed
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Selina Joseph
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Ramla Rashid
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Thabit Athuman
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Anneth Mwasi Tumbo
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Ali Hamad
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Omar Lweno
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Marcel Tanner
- University of BaselBasel, Petersplatz 1, CH-4003 Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health InstituteSocinstrasse 57, 4002 Basel, Switzerland
| | - Seif Shekalaghe
- Ifakara Health Institute, Bagamoyo Research and Training CentreBagamoyo, P.O. Box 74, Tanzania
| | - Claudia A Daubenberger
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health InstituteSocinstrasse 57, 4002 Basel, Switzerland
- University of BaselBasel, Petersplatz 1, CH-4003 Basel, Switzerland
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274
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Kumar AA, Chunda-Liyoka C, Hennek JW, Mantina H, Lee SYR, Patton MR, Sambo P, Sinyangwe S, Kankasa C, Chintu C, Brugnara C, Stossel TP, Whitesides GM. Evaluation of a density-based rapid diagnostic test for sickle cell disease in a clinical setting in Zambia. PLoS One 2014; 9:e114540. [PMID: 25490722 PMCID: PMC4260838 DOI: 10.1371/journal.pone.0114540] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 11/10/2014] [Indexed: 11/18/2022] Open
Abstract
Although simple and low-cost interventions for sickle cell disease (SCD) exist in many developing countries, child mortality associated with SCD remains high, in part, because of the lack of access to diagnostic tests for SCD. A density-based test using aqueous multiphase systems (SCD-AMPS) is a candidate for a low-cost, point-of-care diagnostic for SCD. In this paper, the field evaluation of SCD-AMPS in a large (n = 505) case-control study in Zambia is described. Of the two variations of the SCD-AMPS used, the best system (SCD-AMPS-2) demonstrated a sensitivity of 86% (82–90%) and a specificity of 60% (53–67%). Subsequent analysis identified potential sources of false positives that include clotting, variation between batches of SCD-AMPS, and shipping conditions. Importantly, SCD-AMPS-2 was 84% (62–94%) sensitive in detecting SCD in children between 6 months and 1 year old. In addition to an evaluation of performance, an assessment of end-user operability was done with health workers in rural clinics in Zambia. These health workers rated the SCD-AMPS tests to be as simple to use as lateral flow tests for malaria and HIV.
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Affiliation(s)
- Ashok A. Kumar
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America
| | | | - Jonathan W. Hennek
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Hamakwa Mantina
- Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia
| | - S. Y. Ryan Lee
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Matthew R. Patton
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Pauline Sambo
- Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia
| | | | - Chipepo Kankasa
- Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia
| | - Chifumbe Chintu
- Department of Pediatrics, University Teaching Hospital, Lusaka, Zambia
| | - Carlo Brugnara
- Department of Laboratory Medicine, Children's Hospital Boston, Boston, Massachusetts, United States of America
| | - Thomas P. Stossel
- Hematology Division, Brigham and Women's Hospital, Boston, Massachusetts, United States of America
| | - George M. Whitesides
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail:
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275
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Sornjai W, Khungwanmaythawee K, Svasti S, Fucharoen S, Wintachai P, Yoksan S, Ubol S, Wikan N, Smith DR. Dengue virus infection of erythroid precursor cells is modulated by both thalassemia trait status and virus adaptation. Virology 2014; 471-473:61-71. [DOI: 10.1016/j.virol.2014.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 10/02/2014] [Indexed: 11/29/2022]
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276
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277
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Weatherall DJ. A journey in science: early lessons from the hemoglobin field. Mol Med 2014; 20:478-85. [PMID: 25548947 DOI: 10.2119/molmed.2014.00093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 05/01/2014] [Indexed: 11/06/2022] Open
Abstract
Real innovations in medicine and science are historic and singular; the stories behind each occurrence are precious. At Molecular Medicine we have established the Anthony Cerami Award in Translational Medicine to document and preserve these histories. The monographs recount the seminal events as told in the voice of the original investigators who provided the crucial early insight. These essays capture the essence of discovery, chronicling the birth of ideas that created new fields of research; and launched trajectories that persisted and ultimately influenced how disease is prevented, diagnosed, and treated. In this volume, the Cerami Award Monograph is by David J Weatherall, Founder, Weatherall Institute of Molecular Medicine, Oxford University, John Radcliffe Hospital. A visionary in the field of hemoglobin, this is the story of Professor Weatherall's scientific journey.
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Affiliation(s)
- David J Weatherall
- Weatherall Institute of Molecular Medicine, Oxford University, Oxford, United Kingdom
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278
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Continental-scale footprint of balancing and positive selection in a small rodent (Microtus arvalis). PLoS One 2014; 9:e112332. [PMID: 25383542 PMCID: PMC4226552 DOI: 10.1371/journal.pone.0112332] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 10/06/2014] [Indexed: 01/01/2023] Open
Abstract
Genetic adaptation to different environmental conditions is expected to lead to large differences between populations at selected loci, thus providing a signature of positive selection. Whereas balancing selection can maintain polymorphisms over long evolutionary periods and even geographic scale, thus leads to low levels of divergence between populations at selected loci. However, little is known about the relative importance of these two selective forces in shaping genomic diversity, partly due to difficulties in recognizing balancing selection in species showing low levels of differentiation. Here we address this problem by studying genomic diversity in the European common vole (Microtus arvalis) presenting high levels of differentiation between populations (average FST = 0.31). We studied 3,839 Amplified Fragment Length Polymorphism (AFLP) markers genotyped in 444 individuals from 21 populations distributed across the European continent and hence over different environmental conditions. Our statistical approach to detect markers under selection is based on a Bayesian method specifically developed for AFLP markers, which treats AFLPs as a nearly codominant marker system, and therefore has increased power to detect selection. The high number of screened populations allowed us to detect the signature of balancing selection across a large geographic area. We detected 33 markers potentially under balancing selection, hence strong evidence of stabilizing selection in 21 populations across Europe. However, our analyses identified four-times more markers (138) being under positive selection, and geographical patterns suggest that some of these markers are probably associated with alpine regions, which seem to have environmental conditions that favour adaptation. We conclude that despite favourable conditions in this study for the detection of balancing selection, this evolutionary force seems to play a relatively minor role in shaping the genomic diversity of the common vole, which is more influenced by positive selection and neutral processes like drift and demographic history.
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279
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Campbell-Lee SA, Kittles RA. Red blood cell alloimmunization in sickle cell disease: listen to your ancestors. Transfus Med Hemother 2014; 41:431-5. [PMID: 25670930 PMCID: PMC4280449 DOI: 10.1159/000369513] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 10/21/2014] [Indexed: 11/19/2022] Open
Abstract
Red blood cell (RBC) alloimmunization occurs in approximately 30% of transfused sickle cell disease patients compared to 2-5% of all transfusion recipients. Because RBC transfusion is an important part of therapy in sickle cell disease, the need for additional antigen matching once alloimmunization occurs is problematic and leads to therapeutic limitations. Thus, identification of risk factors would benefit this patient population. Genome-wide analyses, in particular, methods which take into account genetic ancestry such as admixture mapping, could identify molecular markers which could be used to identify immune responders to transfusion.
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280
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Owusu EDA, Visser BJ, Nagel IM, Mens PF, Grobusch MP. The interaction between sickle cell disease and HIV infection: a systematic review. Clin Infect Dis 2014; 60:612-26. [PMID: 25344542 DOI: 10.1093/cid/ciu832] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Human immunodeficiency virus (HIV) and sickle cell disease (SCD) are regarded as endemic in overlapping geographic areas; however, for most countries only scarce data on the interaction between HIV and SCD and disease burden exist. HIV prevalence in SCD patients varies between 0% and 11.5% in published studies. SCD has been suggested to reduce disease progression of HIV into AIDS. Various interactions of antiretroviral therapy with SCD exist. Both SCD and HIV act as common risk factors for stroke, avascular necrosis, severe splenic dysfunction, pulmonary arterial hypertension, and sepsis, which may result in synergistic increase in risk of developing these diseases. No treatment guidelines regarding SCD with HIV coinfection were identified. Available evidence is mainly based on small clinical studies, thus making strong recommendations difficult. An increased effort to elucidate the precise interactions is warranted to better understand both diseases and effect more adequate treatment approaches, especially in view of their geographical coprevalence.
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Affiliation(s)
- Ewurama D A Owusu
- Department of Medical Laboratory Sciences, School of Allied Health Sciences, College of Health Sciences, University of Ghana, Accra Center of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam KIT Biomedical Research, Department of Parasitology, Amsterdam, The Netherlands
| | - Benjamin J Visser
- Center of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam Centre de Recherches Médicales de Lambaréné, Albert Schweitzer Hôpital, Lambaréné, Gabon Institute of Tropical Medicine, University of Tübingen, Germany
| | - Ingeborg M Nagel
- Medical Library, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Petra F Mens
- Center of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam KIT Biomedical Research, Department of Parasitology, Amsterdam, The Netherlands
| | - Martin P Grobusch
- Center of Tropical Medicine and Travel Medicine, Academic Medical Center, University of Amsterdam Centre de Recherches Médicales de Lambaréné, Albert Schweitzer Hôpital, Lambaréné, Gabon Institute of Tropical Medicine, University of Tübingen, Germany
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281
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Lopez AD, Williams TN, Levin A, Tonelli M, Singh JA, Burney PGJ, Rehm J, Volkow ND, Koob G, Ferri CP. Remembering the forgotten non-communicable diseases. BMC Med 2014; 12:200. [PMID: 25604462 PMCID: PMC4207624 DOI: 10.1186/s12916-014-0200-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 10/03/2014] [Indexed: 12/15/2022] Open
Abstract
The forthcoming post-Millennium Development Goals era will bring about new challenges in global health. Low- and middle-income countries will have to contend with a dual burden of infectious and non-communicable diseases (NCDs). Some of these NCDs, such as neoplasms, COPD, cardiovascular diseases and diabetes, cause much health loss worldwide and are already widely recognised as doing so. However, 55% of the global NCD burden arises from other NCDs, which tend to be ignored in terms of premature mortality and quality of life reduction. Here, experts in some of these 'forgotten NCDs' review the clinical impact of these diseases along with the consequences of their ignoring their medical importance, and discuss ways in which they can be given higher global health priority in order to decrease the growing burden of disease and disability.
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Affiliation(s)
- Alan D Lopez
- School of Population and Global Health, The University of Melbourne, Building 379, 207 Bouverie St, Carlton, Melbourne, VIC, 3053, Australia.
| | - Thomas N Williams
- Department of Medicine, Imperial College, St Mary's Hospital, London, W21NY, UK.
- KEMRI/Wellcome Trust Research Programme, PO Box 230, Kilifi, Kenya.
| | - Adeera Levin
- University of British Columbia, St Paul's Hospital, 1081 Burrard Street Rm 6010 A, Vancouver, BC, V6Z1Y8, Canada.
| | - Marcello Tonelli
- , 7th Floor, TRW Building, 3280 Hospital Drive NW, Calgary, Alberta, T2N 4Z6, Canada.
| | - Jasvinder A Singh
- Medicine Service and Center for Surgical Medical Acute care Research and Transitions, VA Medical Center, 510, 20th street South, Birmingham, AL, FOT 805B, USA.
- Department of Medicine at School of Medicine, and Division of Epidemiology at School of Public Health, University of Alabama, 1720 Second Ave. South, Birmingham, AL, 35294-0022, USA.
- Department of Orthopedic Surgery, Mayo Clinic College of Medicine, 200 1st St SW, Rochester, MN, 55905, USA.
| | - Peter G J Burney
- National Heart and Lung Institute, Imperial College, London, UK.
| | - Jürgen Rehm
- Centre for Addiction and Mental Health, Toronto, Canada.
- Clinical Psychology and Psychotherapy, Technical Universität Dresden, Dresden, Germany.
- Addiction Policy, Dalla Lana School of Public Health, University of Toronto (UofT), Toronto, Canada.
- Department of Psychiatry, Faculty of Medicine, UofT, Toronto, Canada.
- Institute of Medical Science, UofT, Toronto, Canada.
| | - Nora D Volkow
- National Institute on Drug Abuse, National Institutes of Health, Rockville, MD, USA.
| | - George Koob
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, 20892-9304, USA.
| | - Cleusa P Ferri
- Institute of Education and Health Sciences, Hospital Alemao Oswaldo Cruz, Rua João Julião, 245 - Bloco D CEP 01323-903, São Paulo, SP, Brazil.
- Department of Psychobiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Botucatu, 862- 1o andar, São Paulo, CEP, 04023-062, Brazil.
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282
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Nnadi E, Manafa P, Okocha E, Chukwuma G, Aneke J. Evaluation of creatine kinase activity and inorganic phosphate concentration in adult nigerian homozygous and heterozygous hemoglobin phenotypes. Ann Med Health Sci Res 2014; 4:697-700. [PMID: 25328777 PMCID: PMC4199158 DOI: 10.4103/2141-9248.141518] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Background: Biochemical parameters vary in subjects with different hemoglobin phenotypes, compared with normal controls. Aim: The aim was to evaluate serum creatine kinase (CK) activity and inorganic phosphate concentrations in Nigerian adults with homozygous and heterozygous hemoglobin phenotypes. Subjects and Methods: A prospective study, carried out at the hematology out-patient clinic of our hospital, a community health center and a private hospital, all in Anambra state. Subjects included hemoglobin phenotypes AA, AS, and SS, in steady state and vaso-occlusive crisis (VOC). Samples were collected for serum CK activity and inorganic phosphate concentrations. Data obtained were analyzed using SPSS 16.0 (SPSS Inc., Chicago IL, USA). Means were compared using the Student's t-test and statistical significance was set at P < 0.05. Results: A total of 100 subjects participated in the study. There was a statistically significant difference in the means of serum CK activity in hemoglobin SS (HbSS) in VOC versus hemoglobin AA (HbAA) (P = 0.01) and HbSS in steady state versus HbAA (P = 0.02) but not in hemoglobin AS (HbAS) versus HbAA (P = 0.79) and HbSS in VOC versus HbSS in steady state (P = 0.06). A statistically significant difference was noted in the means of serum inorganic phosphate concentration in HbSS in VOC versus HbAA (P = 0.01), but not in HbSS in steady state versus HbAA (P = 0.43), HbSS in VOC versus HbSS in steady state (P = 0.09) and HbAS versus HbAA (P = 0.20). Conclusion: Sickle cell disease is a predictor for high serum CK activity and low serum concentration of inorganic phosphate, particularly in VOC. There may be a need to monitor serum CK activity in HbSS subjects presenting with major VOC.
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Affiliation(s)
- Ee Nnadi
- Department of Medical Laboratory Science, Nnamdi Azikiwe University, Nnewi, Anambra State, Nigeria
| | - Po Manafa
- Department of Medical Laboratory Science, Nnamdi Azikiwe University, Nnewi, Anambra State, Nigeria
| | - Ec Okocha
- Department of Hematology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State, Nigeria
| | - Go Chukwuma
- Department of Medical Laboratory Science, Nnamdi Azikiwe University, Nnewi, Anambra State, Nigeria
| | - Jc Aneke
- Department of Hematology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State, Nigeria
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283
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Treadwell MJ, Anie KA, Grant AM, Ofori-Acquah SF, Ohene-Frempong K. Using formative research to develop a counselor training program for newborn screening in Ghana. J Genet Couns 2014; 24:267-77. [PMID: 25193810 DOI: 10.1007/s10897-014-9759-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 08/13/2014] [Indexed: 10/24/2022]
Abstract
Sickle cell disease (SCD), sickle cell trait (SCT) and related conditions are highly prevalent in sub-Saharan Africa. Despite the public health implications, there is limited understanding of the unique needs regarding establishing and implementing extensive screening for newborns and appropriate family counseling. We sought to gain understanding of community attitudes and beliefs about SCD/SCT from counselors and potential counselors in Ghana; obtain their input about goals for counseling following newborn screening; and obtain guidance about developing effective counselor education. Five focus groups with 32 health care providers and health educators from 9 of 10 regions in Ghana were conducted by trained facilitators according to a structured protocol. Qualitative data were coded and categorized to reflect common themes. Saturation was achieved in themes related to genetics/inheritance; common complications of SCD; potential for stigmatization; marital strain; and emotional stress. Misconceptions about SCT as a form of SCD were prevalent as were cultural and spiritual beliefs about the causes of SCD/SCT. Potential positive aspects included affected children's academic achievement as compensation for physical limitations, and family cohesion. This data informed recommendations for content and structure of a counselor training program that was provided to the Ministry of Health in Ghana.
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Affiliation(s)
- Marsha J Treadwell
- Hematology/Oncology Department, UCSF Benioff Children's Hospital Oakland, 747 52nd Street, Oakland, CA, 94609, USA,
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284
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Gomez F, Hirbo J, Tishkoff SA. Genetic variation and adaptation in Africa: implications for human evolution and disease. Cold Spring Harb Perspect Biol 2014; 6:a008524. [PMID: 24984772 DOI: 10.1101/cshperspect.a008524] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Because modern humans originated in Africa and have adapted to diverse environments, African populations have high levels of genetic and phenotypic diversity. Thus, genomic studies of diverse African ethnic groups are essential for understanding human evolutionary history and how this leads to differential disease risk in all humans. Comparative studies of genetic diversity within and between African ethnic groups creates an opportunity to reconstruct some of the earliest events in human population history and are useful for identifying patterns of genetic variation that have been influenced by recent natural selection. Here we describe what is currently known about genetic variation and evolutionary history of diverse African ethnic groups. We also describe examples of recent natural selection in African genomes and how these data are informative for understanding the frequency of many genetic traits, including those that cause disease susceptibility in African populations and populations of recent African descent.
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Affiliation(s)
- Felicia Gomez
- Department of Genetics and Biology, School of Medicine and School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104 Hominid Paleobiology Doctoral Program and The Center for the Advanced Study of Hominid Paleobiology, Department of Anthropology, The George Washington University, Washington, D.C. 20052
| | - Jibril Hirbo
- Department of Genetics and Biology, School of Medicine and School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Sarah A Tishkoff
- Department of Genetics and Biology, School of Medicine and School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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285
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Pays E, Vanhollebeke B, Uzureau P, Lecordier L, Pérez-Morga D. The molecular arms race between African trypanosomes and humans. Nat Rev Microbiol 2014; 12:575-84. [DOI: 10.1038/nrmicro3298] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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286
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Gonçalves BP, Huang CY, Morrison R, Holte S, Kabyemela E, Prevots DR, Fried M, Duffy PE. Parasite burden and severity of malaria in Tanzanian children. N Engl J Med 2014; 370:1799-808. [PMID: 24806160 PMCID: PMC4091983 DOI: 10.1056/nejmoa1303944] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Severe Plasmodium falciparum malaria is a major cause of death in children. The contribution of the parasite burden to the pathogenesis of severe malaria has been controversial. METHODS We documented P. falciparum infection and disease in Tanzanian children followed from birth for an average of 2 years and for as long as 4 years. RESULTS Of the 882 children in our study, 102 had severe malaria, but only 3 had more than two episodes. More than half of first episodes of severe malaria occurred after a second infection. Although parasite levels were higher on average when children had severe rather than mild disease, most children (67 of 102) had high-density infection (>2500 parasites per 200 white cells) with only mild symptoms before severe malaria, after severe malaria, or both. The incidence of severe malaria decreased considerably after infancy, whereas the incidence of high-density infection was similar among all age groups. Infections before and after episodes of severe malaria were associated with similar parasite densities. Nonuse of bed nets, placental malaria at the time of a woman's second or subsequent delivery, high-transmission season, and absence of the sickle cell trait increased severe-malaria risk and parasite density during infections. CONCLUSIONS Resistance to severe malaria was not acquired after one or two mild infections. Although the parasite burden was higher on average during episodes of severe malaria, a high parasite burden was often insufficient to cause severe malaria even in children who later were susceptible. The diverging rates of severe disease and high-density infection after infancy, as well as the similar parasite burdens before and after severe malaria, indicate that naturally acquired resistance to severe malaria is not explained by improved control of parasite density. (Funded by the National Institute of Allergy and Infectious Diseases and others.).
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Affiliation(s)
- Bronner P Gonçalves
- From the Laboratory of Malaria Immunology and Vaccinology (B.P.G., M.F., P.E.D.), Laboratory of Clinical Infectious Diseases-Epidemiology Unit (B.P.G., D.R.P.), and Biostatistics Research Branch (C.-Y.H.), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Rockville, MD; the Seattle Biomedical Research Institute (R.M., M.F., P.E.D.) and the Fred Hutchinson Cancer Research Center (S.H.) - both in Seattle; and the Mother-Offspring Malaria Studies Project, Muheza Designated District Hospital, Muheza, Tanzania (E.K., M.F., P.E.D.)
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287
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Prevalence of deletional alpha thalassemia and sickle gene in a tribal dominated malaria endemic area of eastern India. ISRN HEMATOLOGY 2014; 2014:745245. [PMID: 24808962 PMCID: PMC3967634 DOI: 10.1155/2014/745245] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 02/18/2014] [Indexed: 12/13/2022]
Abstract
Inherited hemoglobin disorders like alpha thalassemia and sickle gene are common in the Indian subcontinent. These disorders in the heterozygous state act as malaria resistance genes and influence the susceptibility to Plasmodium falciparum malaria. There is inadequate knowledge about the epidemiology of these malaria resistance genes in the tribal dominated malaria endemic region of the state of Odisha in eastern India. A cross sectional prevalence study was undertaken in 594 subjects in five tribal populations in this region, namely, Sahara (42.4%), Kutia Kandha (30.0%), Kuda (15.8%), Gond (9.8%), and Oraon (2.0%). Sickling test, Hb electrophoresis, HPLC, and molecular studies were undertaken to diagnose the prevalence of sickle allele, β-thalassemia allele, and deletional alpha thalassemia. Sickle and β thalassemia alleles were found in 13.1% and 3.4% of subjects, respectively. Sickle allele was found both in heterozygous (10.1%) and homozygous state (3.03%). The prevalence of alpha thalassemia was 50.84% with an allelic frequency of 0.37. Both α−3.7 and α−4.2 alpha thalassemia were detected with an allele frequency of 0.33 and 0.04, respectively. The high prevalence of alpha thalassemia and sickle gene in this population is probably due to selection pressure of endemic malaria in this part of India.
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288
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Piel FB, Tatem AJ, Huang Z, Gupta S, Williams TN, Weatherall DJ. Global migration and the changing distribution of sickle haemoglobin: a quantitative study of temporal trends between 1960 and 2000. Lancet Glob Health 2014; 2:e80-9. [PMID: 24748392 PMCID: PMC3986033 DOI: 10.1016/s2214-109x(13)70150-5] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Changes in the geographical distribution of genetic disorders are often thought to happen slowly, especially when compared with infectious diseases. Whereas mutations, genetic drift, and natural selection take place over many generations, epidemics can spread through large populations within a few days or weeks. Nevertheless, population movements can interfere with these processes, and few studies have been done of their eff ect on genetic disorders. We aimed to investigate the eff ect of global migration on the distribution of the sickle-cell gene-the most common and clinically significant haemoglobin structural variant. METHODS For each country, we extracted data from the World Bank’s Global Bilateral Migration Database about international human migrations between 1960 and 2000. We combined this information with evidence-based estimates of national HbS allele frequencies, generated within a Bayesian geostatistical framework, to analyse temporal changes in the net numbers of migrants, and classified countries with an index summarising these temporal trends. FINDINGS The number of international migrants increased from 92.6 million in 1960, to 165.2 million in 2000. The estimated global number of migrants with HbS increased from about 1.6 million in 1960, to 3.6 million in 2000. This increase was largely due to an increase in the number of migrants from countries with HbS allele frequencies higher than 10%, from 3.1 million in 1960, to 14.2 million in 2000. Additionally, the mean number of countries of origin for each destination country increased from 70 (SE 46) in 1960, to 98 (48) in 2000, showing an increasing diversity in the network of international migrations between countries. Our index of change map shows a patchy distribution of the magnitude of temporal changes, with the highest positive and negative values scattered across all continents. INTERPRETATION Global human population movements have had a substantial eff ect on the distribution of the HbS gene. Population movements can create a long-term burden on health-care systems. Our findings, which emphasise countries in which migration fluxes are changing the most, should increase awareness about the global burden of haemoglobinopathies and encourage policy makers to implement specific public health interventions, such as screening programmes and genetic counselling. FUNDING Wellcome Trust, European Research Council, Bill & Melinda Gates Foundation, National Institute of Allergy and Infectious Diseases-National Institutes of Health, the Research and Policy for Infectious Disease Dynamics program, Fogarty International Center.
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Affiliation(s)
- Frédéric B Piel
- Evolutionary Ecology of Infectious Disease Group, Tinbergen Building, Department of Zoology, University of Oxford, Oxford, UK
- Global Sickle Cell Disease Network, Toronto, ON, Canada
| | - Andrew J Tatem
- Department of Geography and Environment, University of Southampton, Southampton, UK
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - Zhuojie Huang
- Center for Infectious Disease Dynamics and Department of Biology, Pennsylvania State University, PA, USA
| | - Sunetra Gupta
- Evolutionary Ecology of Infectious Disease Group, Tinbergen Building, Department of Zoology, University of Oxford, Oxford, UK
| | - Thomas N Williams
- Global Sickle Cell Disease Network, Toronto, ON, Canada
- Kenya Medical Research Institute–Wellcome Trust Programme, Centre for Geographic Medicine Research-Coast, Kilifi District Hospital, Kilifi, Kenya
- Department of Medicine, Imperial College, St Mary's Hospital, London, UK
| | - David J Weatherall
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
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289
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Harper KN, Armelagos GJ. Genomics, the origins of agriculture, and our changing microbe-scape: time to revisit some old tales and tell some new ones. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2013; 152 Suppl 57:135-52. [PMID: 24249593 PMCID: PMC7159788 DOI: 10.1002/ajpa.22396] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Though agriculture is often viewed as one of humanity's crowning achievements, skeletal evidence indicates that dependence on domesticated plants and animals was accompanied by an increase in infectious disease. Scientists have proposed that many important infections emerged in the period following the advent of agriculture, as a result of newly dense populations and novel proximity to domestic animals that served as reservoirs for novel pathogens. Here, we review genomic evidence regarding pathogen origins, analyzing these data using the epidemiological transition framework. Genetic information has forced us to reconsider how and when many important pathogens emerged; it appears that a number of infections thought to result from contact with domesticated animals arose much earlier than agriculture was adopted. We also consider the broader effect of agriculture upon the microbiome, exploring potential consequences for human health. We end by discussing the changes in the human microbe-scape we are likely to see in the future.
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Affiliation(s)
- Kristin N Harper
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032
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290
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Takahashi Y, Nagata N, Kawata M. Antagonistic selection factors induce a continuous population divergence in a polymorphism. Heredity (Edinb) 2013; 112:391-8. [PMID: 24281546 DOI: 10.1038/hdy.2013.117] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 09/03/2013] [Accepted: 09/06/2013] [Indexed: 11/09/2022] Open
Abstract
Understanding the relative importance of selection and stochastic factors in population divergence of adaptive traits is a classical topic in evolutionary biology. However, it is difficult to separate these factors and detect the effects of selection when two or more contrasting selective factors are simultaneously acting on a single locus. In the damselfly Ischnura senegalensis, females exhibit color dimorphism and morph frequencies change geographically. We here evaluated the role of selection and stochastic factors in population divergence of morph frequencies by comparing the divergences in color locus and neutral loci. Comparisons between population pairwise FST for neutral loci and for the color locus did not detect any stochastic factors affecting color locus. Although comparison between population divergence in color and neutral loci using all populations detected only divergent selection, we detected two antagonistic selective factors acting on the color locus, that is, balancing and divergent selection, when considering geographical distance between populations. Our results suggest that a combination of two antagonistic selective factors, rather than stochastic factors, establishes the geographic cline in morph frequency in this system.
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Affiliation(s)
- Y Takahashi
- Frontier Research Institute for Interdisciplinary Sciences, International Advanced Research and Education Organization, Tohoku University, Sendai, Japan
| | - N Nagata
- Division of Ecology and Evolutionary Biology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - M Kawata
- Division of Ecology and Evolutionary Biology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
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291
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Piel FB. [Sickle-cell disease: geographical distribution and population estimates]. Med Sci (Paris) 2013; 29:965-7. [PMID: 24280499 DOI: 10.1051/medsci/20132911012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Frédéric B Piel
- University of Oxford, Tinbergen building, Department of Zoology, South Parks Road, OX1 3PS, Oxford, Royaume-Uni
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292
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The distribution of haemoglobin C and its prevalence in newborns in Africa. Sci Rep 2013; 3:1671. [PMID: 23591685 PMCID: PMC3628164 DOI: 10.1038/srep01671] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 04/02/2013] [Indexed: 01/07/2023] Open
Abstract
Haemoglobin C (HbC) is one of the commonest structural haemoglobin variants in human populations. Although HbC causes mild clinical complications, its diagnosis and genetic counselling are important to prevent inheritance with other haemoglobinopathies. Little is known about its contemporary distribution and the number of newborns affected. We assembled a global database of population surveys. We then used a Bayesian geostatistical model to create maps of HbC frequency across Africa and paired our predictions with high-resolution demographics to calculate heterozygous (AC) and homozygous (CC) newborn estimates and their associated uncertainty. Data were too sparse outside Africa for this methodology to be applied. The highest frequencies were found in West Africa but HbC was commonly found in other parts of the continent. The expected annual numbers of AC and CC newborns in Africa were 672,117 (interquartile range (IQR): 642,116-705,163) and 28,703 (IQR: 26,027-31,958), respectively. These numbers are about two times previous estimates.
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293
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Bucknor MD, Goo JS, Coppolino ML. The risk of potential thromboembolic, renal and cardiac complications of sickle cell trait. Hemoglobin 2013; 38:28-32. [PMID: 24099594 DOI: 10.3109/03630269.2013.832689] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Many complications of sickle cell trait have been well-established, but associations with additional disease states remain controversial. We conducted a retrospective cohort study to examine the frequency of receiving a diagnosis of thromboembolism, pulmonary embolism (PE), ischemic stroke, renal disease (acute, chronic), coronary artery disease (CAD) and congestive heart failure (CHF) in patients with sickle cell trait. A total of 13,964 adult African Americans registered in the Kaiser Permanente Northern California (KPNC) health system (Oakland, CA, USA), were included based on laboratory and diagnostic code data for the years 1995-2008: 2642 with sickle cell trait, 11,183 with normal hemoglobin (Hb) and 139 with sickle cell disease. Disease outcomes were obtained from coded diagnoses. The adjusted relative risk of PE and chronic kidney disease in sickle cell trait patients compared to patients with normal Hb were 1.37 [95% confidence interval (CI) 1.07-1.75] and 1.13 (95% CI 1.03-1.23), respectively. There were no other significant differences in the outcomes for sickle cell trait patients compared to patients with normal Hb.
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Affiliation(s)
- Matthew D Bucknor
- Department of Radiology and Biomedical Imaging; University of California San Francisco, San Francisco , California , USA
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294
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Gong L, Parikh S, Rosenthal PJ, Greenhouse B. Biochemical and immunological mechanisms by which sickle cell trait protects against malaria. Malar J 2013; 12:317. [PMID: 24025776 PMCID: PMC3847285 DOI: 10.1186/1475-2875-12-317] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 08/31/2013] [Indexed: 12/18/2022] Open
Abstract
Sickle cell trait (HbAS) is the best-characterized genetic polymorphism known to protect against falciparum malaria. Although the protective effect of HbAS against malaria is well known, the mechanism(s) of protection remain unclear. A number of biochemical and immune-mediated mechanisms have been proposed, and it is likely that multiple complex mechanisms are responsible for the observed protection. Increased evidence for an immune component of protection as well as novel mechanisms, such as enhanced tolerance to disease mediated by HO-1 and reduced parasitic growth due to translocation of host micro-RNA into the parasite, have recently been described. A better understanding of relevant mechanisms will provide valuable insight into the host-parasite relationship, including the role of the host immune system in protection against malaria.
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Affiliation(s)
- Lauren Gong
- University of California, Box 1234, San Francisco 94143, CA, USA.
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295
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Weinkam P, Sali A. Mapping polymerization and allostery of hemoglobin S using point mutations. J Phys Chem B 2013; 117:13058-68. [PMID: 23957820 DOI: 10.1021/jp4025156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hemoglobin is a complex system that undergoes conformational changes in response to oxygen, allosteric effectors, mutations, and environmental changes. Here, we study allostery and polymerization of hemoglobin and its variants by application of two previously described methods: (i) AllosMod for simulating allostery dynamics given two allosterically related input structures and (ii) a machine-learning method for dynamics- and structure-based prediction of the mutation impact on allostery (Weinkam et al. J. Mol. Biol. 2013, 425, 647-661), now applicable to systems with multiple coupled binding sites, such as hemoglobin. First, we predict the relative stabilities of substates and microstates of hemoglobin, which are determined primarily by entropy within our model. Next, we predict the impact of 866 annotated mutations on hemoglobin's oxygen binding equilibrium. We then discuss a subset of 30 mutations that occur in the presence of the sickle cell mutation and whose effects on polymerization have been measured. Seven of these HbS mutations occur in three predicted druggable binding pockets that might be exploited to directly inhibit polymerization; one of these binding pockets is not apparent in the crystal structure, but only in structures generated by AllosMod. For the 30 mutations, we predict that mutation-induced conformational changes within a single tetramer tend not to significantly impact polymerization; instead, these mutations more likely impact polymerization by directly perturbing a polymerization interface. Finally, our analysis of allostery allows us to hypothesize why hemoglobin evolved to have multiple subunits and a persistent low frequency sickle cell mutation.
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Affiliation(s)
- Patrick Weinkam
- Department of Bioengineering and Therapeutic Sciences, ‡Department of Pharmaceutical Chemistry, and California Institute for Quantitative Biosciences (QB3), University of California, San Francisco , San Francisco, California 94158, United States
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296
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Tewari S, Rees D. Morbidity pattern of sickle cell disease in India: a single centre perspective. Indian J Med Res 2013; 138:288-90. [PMID: 24135171 PMCID: PMC3818589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Sanjay Tewari
- Clinical Research Fellow in Paediatric Haematology, King's College Hospital, Denmark Hill, London, SE5 9RS, UK,For correspondence:
| | - David Rees
- Professor of Paediatric Haematology, King's College Hospital, Denmark Hill, London, SE5 9RS, UK
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297
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Bañuls AL, Thomas F, Renaud F. Of parasites and men. INFECTION GENETICS AND EVOLUTION 2013; 20:61-70. [PMID: 23954419 DOI: 10.1016/j.meegid.2013.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 08/05/2013] [Accepted: 08/07/2013] [Indexed: 01/14/2023]
Abstract
The living world has evolved and is evolving through interspecific relationships between organisms. The diversity of these interactions is enormous going from mutualism to parasitism. Humans live with a multitude of microorganisms, essential for their biology. However, interactions are not always advantageous. Indeed, many organisms might become pathogens, such as the Plasmodium species, the causative agents of malaria. Like many other microorganisms, they are «Machiavellian» in their capacity to elaborate a range of reproduction strategies, giving them a huge advantage in terms of adaptation. Here, we discuss the role played by parasites in the ecology and evolution of living organisms and particularly of humans. In the study of infectious diseases, humans are legitimately the focal point, although they represent only one ecosystem among many others and not taking this into account certainly biases our global view of the system. Indeed, we know only a minimal fraction of the microorganisms we live with. However, parasites have shaped and are still shaping the human genome. Several genetic signatures are the proofs of the selection pressures by parasites that humankind has endured during its evolution. But, ultimately, what are the solutionsfor living with pathogens? Should we eradicate them or should we learn how to control and manage them?
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Affiliation(s)
- Anne-Laure Bañuls
- Laboratoire MIVEGEC (UMR CNRS 5290-IRD 224 - Universités Montpellier 1 et 2), Institut de Recherche pour le Développement (IRD), PO Box 64501, 34394 Montpellier, France.
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298
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Stevens GA, Finucane MM, De-Regil LM, Paciorek CJ, Flaxman SR, Branca F, Peña-Rosas JP, Bhutta ZA, Ezzati M. Global, regional, and national trends in haemoglobin concentration and prevalence of total and severe anaemia in children and pregnant and non-pregnant women for 1995-2011: a systematic analysis of population-representative data. LANCET GLOBAL HEALTH 2013; 1:e16-25. [PMID: 25103581 PMCID: PMC4547326 DOI: 10.1016/s2214-109x(13)70001-9] [Citation(s) in RCA: 1058] [Impact Index Per Article: 96.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Background Low haemoglobin concentrations and anaemia are important risk factors for the health and development of women and children. We estimated trends in the distributions of haemoglobin concentration and in the prevalence of anaemia and severe anaemia in young children and pregnant and non-pregnant women between 1995 and 2011. Methods We obtained data about haemoglobin and anaemia for children aged 6–59 months and women of childbearing age (15–49 years) from 257 population-representative data sources from 107 countries worldwide. We used health, nutrition, and household surveys; summary statistics from WHO's Vitamin and Mineral Nutrition Information System; and summary statistics reported by other national and international agencies. We used a Bayesian hierarchical mixture model to estimate haemoglobin distributions and systematically addressed missing data, non-linear time trends, and representativeness of data sources. We quantified the uncertainty of our estimates. Findings Global mean haemoglobin improved slightly between 1995 and 2011, from 125 g/L (95% credibility interval 123–126) to 126 g/L (124–128) in non-pregnant women, from 112 g/L (111–113) to 114 g/L (112–116) in pregnant women, and from 109 g/L (107–111) to 111 g/L (110–113) in children. Anaemia prevalence decreased from 33% (29–37) to 29% (24–35) in non-pregnant women, from 43% (39–47) to 38% (34–43) in pregnant women, and from 47% (43–51) to 43% (38–47) in children. These prevalences translated to 496 million (409–595 million) non-pregnant women, 32 million (28–36 million) pregnant women, and 273 million (242–304 million) children with anaemia in 2011. In 2011, concentrations of mean haemoglobin were lowest and anaemia prevalence was highest in south Asia and central and west Africa. Interpretation Children's and women's haemoglobin statuses improved in some regions where concentrations had been low in the 1990s, leading to a modest global increase in mean haemoglobin and a reduction in anaemia prevalence. Further improvements are needed in some regions, particularly south Asia and central and west Africa, to improve the health of women and children and achieve global targets for reducing anaemia. Funding Bill & Melinda Gates Foundation, Grand Challenges Canada, and the UK Medical Research Council.
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Affiliation(s)
- Gretchen A Stevens
- Department of Health Statistics and Information Systems, WHO, Geneva, Switzerland
| | - Mariel M Finucane
- Gladstone Institutes, University of California, San Francisco, CA, USA
| | - Luz Maria De-Regil
- Department of Nutrition for Health and Development, WHO, Geneva, Switzerland
| | | | - Seth R Flaxman
- School of Computer Science and Heinz College, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Francesco Branca
- Department of Nutrition for Health and Development, WHO, Geneva, Switzerland
| | | | - Zulfiqar A Bhutta
- Division of Women and Child Health, Aga Khan University, Karachi, Pakistan
| | - Majid Ezzati
- Department of Epidemiology and Biostatistics, MRC-HPA Centre for Environment and Health, Imperial College London, London, UK.
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299
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Affiliation(s)
- Russell E. Ware
- Texas Children's Center for Global Health, Texas Children's Hospital, Houston, Texas, United States of America
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
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300
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Piel FB, Howes RE, Nyangiri OA, Moyes CL, Williams TN, Weatherall DJ, Hay SI. Online biomedical resources for malaria-related red cell disorders. Hum Mutat 2013; 34:937-44. [PMID: 23568771 PMCID: PMC3738938 DOI: 10.1002/humu.22330] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 04/01/2013] [Indexed: 01/01/2023]
Abstract
Warnings about the expected increase of the global public health burden of malaria-related red cell disorders are accruing. Past and present epidemiological data are necessary to track spatial and temporal changes in the frequencies of these genetic disorders. A number of open access biomedical databases including data on malaria-related red cell disorders have been launched over the last two decades. Here, we review the content of these databases, most of which focus on genetic diversity, and we describe a new epidemiological resource developed by the Malaria Atlas Project. To tackle upcoming public health challenges, the integration of epidemiological and genetic data is important. As many countries are considering implementing national screening programs, strategies to make such data more accessible are also needed.
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Affiliation(s)
- Frédéric B Piel
- Spatial Ecology and Epidemiology Group, Tinbergen Building, Department of Zoology, University of Oxford, South Parks Road, Oxford, United Kingdom.
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