Heterozygote advantage, one coin two sides
There are some genetic diseases that are recessive, that means you need two copies of mutation of this gene to get disease, but in some case you benefit from the mutation if you only have one mutation copy, and the other copy is normal. These diseases genes with heterozygote advantage are:
sickle-cell anemia against malaria
cystic fibrosis against typhoid and tuberculosis
triose phosphate isomerase deficiency against oxidative stress
