Journal Article

Malaria continues to select for sickle cell trait in Central Africa

Becquart, Pierre, Elguero, Eric, Nkoghe, Dieudonné, Durand, Patrick, Sica, Lucas, Rougeron, Virginie, Roche, Benjamin, Ollomo, Benjamin, Délicat-Loembet, Lucrèce M., Arnathau, Céline, Renaud, François, Gonzalez, Jean-Paul, Leroy, Eric M., Ayala, Francisco J., Prugnolle, Franck

2015

Overview

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 toPlasmodium falciparummalaria 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 ofPlasmodiumwere detected by PCR followed by sequencing of a 201-bp fragment of cytochromeb.An increase of 10% inP. falciparummalaria 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.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Age Factors / alleles / Anemia, Sickle Cell - epidemiology / Anemia, Sickle Cell - genetics / Base Sequence / Biological Evolution / Biological Sciences / Central Africa / children / Chromatography, High Pressure Liquid / Cohort Studies / Cytochrome / death / Gabon - epidemiology / Health risks / Hemoglobin / Human populations / Humans / Life Sciences / Liquid chromatography / Malaria / Malaria, Falciparum - epidemiology / Malaria, Falciparum - genetics / Migration / Molecular Sequence Data / people / Plasmodium - genetics / Plasmodium falciparum / Polymerase Chain Reaction / Protozoa / Public health / Selection, Genetic / Sequence Analysis, DNA / sickle cell anemia / Sickle cell disease / Species Specificity / Vector-borne diseases / World Health Organization