Some heterozygote advantages in humans are:
- People with sickle-cell trait are resistant to malaria, but people with sickle-cell disease tend to die young.
- Depending of the source we believe, people with one copy of a cystic fibrosis allele are immune to tuberculosis, or cholera, or typhoid fever (or two of them or all the three!) (it has been debunked).
- People with one copy the CCR5-delta 32 allele are resistant to AIDS, when they have two copies, they are immune to AIDS, but they are at higher risk for West Nile virus disease complications.
- People with Niemann-Pick disease type C are completely immune to ebolavirus-related hemorrhagic fever, and their heterozygous parents seem to be resistant against this disease caused by a filovirus.
So, I wonder what would a heterozygote advantage against pork tapeworm (Taenia solium) look like. I ask because my story is set in a future where tapeworms have evolved to be able to survive MUCH higher temperatures, and therefore, it has become more difficult to cook mammalian meats without burning them. Therefore, many humans died from neurocysticercosis.
The molecular mechanism behind this is three genes linked to Hirschsprung's disease (RET, EDNRB, and GDNF, respectively on chromosome 10, on chromosome 13, and on chromosome 5).