Distribution of the Sickle-Cell Trait in Uganda, and its Ethnological Significance

Lehmann, H.; Raper, A. B.

doi:10.1038/164494a0

Cited by 69 publications

(32 citation statements)

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“…Each year, about 300 000 infants are born with major haemoglobin disorders—including more than 200 000 cases of sickle-cell anaemia in Africa 4. The prevalence of sickle-cell trait, which confers protection against malaria, varies by geographic location between 10% and 40% across equatorial Africa and decreases to between 1% and 2% on the North African coast and <1% in South Africa, where malaria is less prevalent 4 5 6. Immunological selection pressure due to malaria has resulted in high frequencies of the mutant gene in areas of high malarial transmission 4.…”

Section: Epidemiologymentioning

confidence: 99%

Pneumococcal infections and sickle cell disease in Africa: does absence of evidence imply evidence of absence?

Obaro

2009

Archives of Disease in Childhood

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Sickle cell disease (SCD) compromises host immune defence and predisposes to infections from several encapsulated bacteria, viruses and parasites. While penicillin prophylaxis and pneumococcal vaccination are established routine care in developed countries, such preventive measures are poorly structured or non-existent in most malaria-endemic, developing country settings. In fact, the role of pneumcoccal infections has been brought into question, based on available data. The role of invasive pneumococcal disease in child mortality has now been established from population-based studies in such settings. Thus, it may be unsafe to assume that children with SCD are less susceptible. Whether malaria endemicity increases susceptibility to other encapsulated bacteria such as salmonella infections is a critical but unanswered question that will inform the development of appropriate preventive measure policies in this setting. Research to clearly define the leading cause of infection-related morbidity and mortality in SCD in Africa should be encouraged.

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Section: Epidemiologymentioning

confidence: 99%

Pneumococcal infections and sickle cell disease in Africa: does absence of evidence imply evidence of absence?

Obaro

2009

Archives of Disease in Childhood

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“…In this paper, they disputed Lehmann's (1954) admixture hypothesis (based on Lehmann & Raper 1949) as being 'difficult to imagine how [inter-tribal] intermarriage could have caused differences as large as those found...Also [one] would expect [if such admixture] that there would be differences in the blood group frequencies to be associated with the sickling rate, but this does not occur,' (Foy & Kondi 1954, p. 296). They also diminished support of their earlier suggestion (Foy & Kondi 1951) that reproductive over-compensation provided a viable model.…”

Section: History Of Genetic Research In Sickle-cell Anemiamentioning

confidence: 78%

“…Raper compared the frequencies of sickle-cell disease in the United States with those found in Africa to underscore how the substantially lower incidence of sickle-cell trait found in the U.S. black population was due to significant admixture of post slave trade black Africans with indigenous Caucasian and Native American individuals. Lehmann (1953) summarized his earlier research with Raper (Lehmann & Raper 1949) and again emphasized a theory of admixture to principally explain the existence of high frequencies of carriers in certain portions of Uganda. In his paper, Lehmann did acknowledge Anthony Allison's theoretical conclusions (see below) regarding the selective advantage of heterozygotes as playing a partial role in the maintenance of high percentages of sickle-cell carriers.…”

Section: History Of Genetic Research In Sickle-cell Anemiamentioning

confidence: 96%

“…Lehmann & Raper (1949) based their theory on anthropomorphic evidence by drawing attention to the fact that there was a strong correlation between tribal groups who possessed higher percentages of the sickle-cell trait with a qualitative assessment of the degree to which a tribal group could be characterized as originating within the African continent. Put another way, Lehmann and Raper argued that the higher proportion of admixing (a function largely of migration/intermarriage) a tribal population appeared to have undergone, the lower the frequency of sickle-cell trait contained by the members of the population.…”

Section: History Of Genetic Research In Sickle-cell Anemiamentioning

confidence: 99%

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‘Untangling Sickle-cell Anemia and the Teaching of Heterozygote Protection’

Howe

2007

Sci Educ

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Introductory biology textbooks often use the example of sickle-cell anemia to illustrate the concept of heterozygote protection. Ordinarily scientists expect the frequency of a gene associated with a debilitating illness would be low owing to its continual elimination by natural selection. The gene that causes sickle-cell anemia, however, has a relatively high frequency in many parts of the world. Historically, scientists proposed and defended several alternative theories to account for this anomaly, though it is now widely recognized among the scientific community that high frequencies of the gene reflect its benefit to heterozygotes against malaria. Textbooks normally develop this concept with reference to the often-used maps of Africa showing how in areas where the frequency of the sickle-cell gene is high, there is also higher exposure to the disease malaria. While sickle-cell anemia is often the example of choice for explaining and illustrating the concept of heterozygote protection, the present paper argues that exploring the history of scientific research behind our contemporary understanding has advantages for helping students understand multiple factors related to population genetics (e.g. mutation, gene flow, drift) in addition to heterozygote protection. In so doing, this approach invites students to evaluate the legitimacy of their own alternative conceptions about introductory population genetics or about the genetics of the disease sickle-cell anemia. The various historical theories scientists proposed and defended often resemble those of students who first learn about the disease. As such, a discussion of how scientists reached consensus about the role of heterozygote protection may help students understand and appreciate what are now recognized to be limitations in the views they bring to their classrooms. The paper concludes by discussing the ramifications of this approach in potentially helping students to examine certain aspects of the nature of science.

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“…The late 1940s saw an abundance of research on sickle cells in French, Portuguese, Belgian, and British colonial Empires in Africa (Evans, 1944;English, 1945;Findlay, Robertson, Zacharias, 1946;Robertson, Findlay, 1947;Gosden, Reid, 1948;Beet, 1949;Lehmann, Raper, 1949;Van den Berghe, Janssen, 1950;Hiernaux, 1952;Jelliffe, Humphreys, 1952;Lehmann, Cutbush, 1952;Foy, Kondi, Hargreaves, 1952;Singer, 1953;Foy et al, 1954).…”

Section: The Racial Specificity Of Sickle Cells In Africamentioning

confidence: 99%

Entre negros e miscigenados: a anemia e o traço falciforme no Brasil nas décadas de 1930 e 1940

Cavalcanti

Maio

2011

Hist. cienc. saude-Manguinhos

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Aborda os estudos médicos e científicos sobre a anemia falciforme publicados no Brasil nas décadas de 1930 e 1940. A miscigenação foi apontada, pela maioria dos médicos e cientistas, como interferência significativa na epidemiologia da doença no país. Destaca a atuação do hematologista do Instituto Oswaldo Cruz Ernani Martins da Silva, que efetuou análises sanguíneas no interior no Brasil para determinar os grupos populacionais miscigenados e puros, baseado na identificação de hemácias falciformes e da distribuição racial dos grupos sanguíneos. Analisam-se as ambivalências existentes na associação entre a anemia falciforme e 'raça negra' durante os anos de 1930 e 1940 no Brasil.

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Distribution of the Sickle-Cell Trait in Uganda, and its Ethnological Significance

Cited by 69 publications

References 1 publication

Pneumococcal infections and sickle cell disease in Africa: does absence of evidence imply evidence of absence?

Pneumococcal infections and sickle cell disease in Africa: does absence of evidence imply evidence of absence?

‘Untangling Sickle-cell Anemia and the Teaching of Heterozygote Protection’

Entre negros e miscigenados: a anemia e o traço falciforme no Brasil nas décadas de 1930 e 1940

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