Viewing a single comment thread. View all comments

fingawkward t1_ja8foyo wrote

Reply to comment by [deleted] in Is there a genetic disease where the heterozygote has more severe disease symptoms than the homozygote? by Altranite-

It was my understanding that being heterozygous for sickle cell confers advantage in resistance to malaria while homozygocity causes sickle cell disease.

15

sparky_1966 t1_ja8p8n1 wrote

You are correct, heterozygous provides some protection from malaria and homozygous causes sickle cell. The heterozygotes are still not normal and are less healthy than normal people, but the negative pressure from malaria is strong enough that it's a net gain.

5

sa2bcity t1_ja8x9in wrote

You are right. In this case, however, the sickle-cell allele is the one that confers the advantage.

2