<unk>  refers to inherited changes in the DNA of<unk> s which increase<unk>  to<unk>  and result in increased survival of individuals with those<unk>  changes. The existence of these genotypes is likely due to evolutionary pressure exerted by parasites of the genus Plasmodium which cause<unk> . Since<unk>  infects red blood cells, these<unk>  changes are most common alterations to molecules essential for red blood cell function (and therefore parasite survival), such as hemoglobin or other cellular proteins or enzymes of red blood cells. These alterations generally protect red blood cells from invasion by Plasmodium parasites or replication of parasites within the red blood cell. These inherited changes to hemoglobin or other characteristic proteins, which are critical and rather invariant features of mammalian biochemistry, usually cause some kind of inherited disease. Therefore, they are commonly referred to by the names of the blood disorders associated with them, including sickle-cell disease, thalassemia, glucose-6-phosphate dehydrogenase deficiency, and others. These blood disorders cause increased morbidity and mortality in areas of the world where<unk>  is less prevalent.
Human genetic resistance to malaria
Susceptibility and severity of infections in pregnancy
Vaccine-preventable diseases
Effects of parasitic worms on the immune system
Free-living Amoebozoa infection
Rabies in animals
Use of fetal tissue in vaccine development
risks of Pneumocystis pneumonia