The hereditary condition known as sickle-cell anemia affects about 72,000 people. It is most common in African Americans, occurring in around one in 500 births.
Sickle-cell anemia refers to a flaw in the gene that carries the instructions for hemoglobin, which is an important component of red blood cells. As a result of this flaw, the cells, rather than being round, as normal, take on the sickle shape that gives the condition its name. This is more than an aesthetic concern; the cells are stiff and cannot easily go through blood vessels.
Hemoglobin is responsible for carrying oxygen around the body. When red blood cells– which contain hemoglobin– get stuck, the hemoglobin is unable to make its deliveries, and not enough oxygen gets through. This leads to pain and weakness.
In addition to being misshapen, the affected red blood cells have a markedly shorter lifespan. Red blood cells are expected to live around four months, and are replenished about that often. Sickle cells live only about two weeks, so they don’t get replaced fast enough, leading to the weakness and fatigue of anemia.
Sickle-cell is a recessive genetic trait, meaning that the anemia affects people with two copies of the flawed gene. Someone with only one copy is an unaffected carrier of the trait, meaning he or she doesn’t have the condition but can pass the tendency to his or her children. There is a connection between being a carrier and lowered vulnerability to malaria which can be beneficial in areas where malaria is common.
Babies with only one parent with the sickle-cell trait won’t be anemic but about half of them will be carriers themselves. About half of the children of two carriers will also be carriers of the trait, and a quarter will end up with the condition. Genetic testing can tell you if you or your partner or both is a carrier; only testing the fetus will tell you whether that particular child will be born with the condition. Even couples who are both carriers can safely have children, however.
If you are or might be a carrier of sickle-cell, talk to your doctor if you plan to have children to decide on the best course of action. As we’ll discuss, the condition can be treated, so while the risk is something to consider it isn’t necessarily a bar.