Heterozygous sickle cell anemia gives protection against -
G6PD
Malaria
Thalassemia
Dengue fever
The possession of the sickle cell allele protects these individuals against malaria because the parasite dies when potassium leaks out of RBCs as they become sickle-shaped.
Types of anemia that have protective effect against P. falciparum malaria : -
G6PD deficiency, Sickle cell anemia, Thalassemia, HbC, Pyruvate kinase deficiency