However, using the best imputation model for the data, we obtained unbiased estimates for the genetic effects, and association signals of the HBA2 gene on malaria positivity.
Our findings also raise the possibility that other unstable hemoglobins such as HbE and unpaired α-globin chains (in the case of β-thalassemia) protect against life-threatening malaria by a similar mechanism.
In malarial environments, the loss of one or two copies of the four α globin genes in normal diploid genotypes confers resistance (lower mortality) to malaria.
The frequency of placental P. falciparum infection and systemic malaria infection after delivery showed no consistent relationship to alpha-globin genotype.
A total of 664 DNA samples were screened for alpha-thalassemia 2 and alpha-thalassemia 1 caused respectively by either deletion of one or both of the duplicated alpha-globin genes. alpha-Thalassemia 2 was detected in high frequencies in coastal and lowland regions where malaria has been holo- to hyperendemic but in low frequencies in non-malarious highland regions.