Basically this mutation is shown to protect against malaria, but it causes an issue with producing a molecule needed for the creation of ATP (energy your body needs)

So while they can offer a protective effect to the subject they could need transfusions or other treatment to stay healthy.

Subject 1 & 2 had similar biomarkers, and subject 3 had different markers causing a type of misread that made them transfusion dependent.

That’s my understanding at least