[Aquinasfan]

When it's preventing one's death by malaria, I think it would generally be considered to be doing more good than harm.

A list of complications resulting from sickle cell disease:

recurrent aplastic and hemolytic crises resulting in anemia and gallstones
multisystem disease (kidney, liver, lung)
narcotic abuse
splenic sequestration syndrome
acute chest syndrome
erectile dysfunction (as a result of priapism)
blindness/visual impairment
neurologic symptoms and stroke
joint destruction
gallstones
infection, including pneumonia, cholecystitis
(gallbladder), osteomyelitis (bone), and urinary tract infection
parvovirus B19 infection resulting in aplastic crisis
tissue death of the kidney
loss of function of the spleen
leg ulcers
death

MedicinePlus Medical Encyclopedia

I suspect this is why sickle cell disease is considered by medical doctors as a disease.

[Virginia-American]

I suspect this is why sickle cell disease is considered by medical doctors as a disease.

Just don't confuse it with having one copy of the gene; that's a tremendous benefit.