Candidates include the inherited condition sickle cell anaemia, in which a single gene defect disrupts haemoglobin production with serious consequences for patients, who suffer anaemia because their bodies are starved of oxygen.

Source: https://www.theguardian.com/science/2023/feb/05/how-far-should-we-go-with-gene-editing-in-pursuit-of-the-perfect-human

They were therefore able to live long enough in spite of the recurrent burden of extremely painful sickle cell anaemia symptoms to have children of their own even though their quality of life was very poor and they frequently died in young adulthood.

Source: https://thenationonlineng.net/malaria-ii/

Those with sickle cell anaemia have inherited one sickle cell gene each from their mother and father, which is why pre-conceptual screening is important."

Source: https://www.mylondon.news/news/east-london-news/sickle-cell-disease-leaves-weak-27810862