Trait vs. disease
Hemoglobin is the protein in red blood cells that carries oxygen. People with sickle cell disease inherit two sickle genes, and their red cells can bend into a sickle shape, causing pain, anemia, infections and organ damage. People with sickle cell trait have one sickle gene and one normal gene. Their bodies make enough normal hemoglobin, so most never have symptoms.
Rarely, people with the trait run into problems under extreme conditions, such as intense exercise in heat, severe dehydration or very high altitude. That's why US college athletics (NCAA) checks athletes' sickle cell trait status.
Who has it?
About 1 in 13 Black or African American babies in the US is born with sickle cell trait. It's also found in people with roots in sub-Saharan Africa, the Middle East, India (especially some communities in central and western India), the Mediterranean and Latin America.
Why it matters for your kids
If both partners have sickle cell trait, each pregnancy has a 1 in 4 chance of sickle cell disease, a 2 in 4 chance of trait, and a 1 in 4 chance of neither. Sickle cell disease can also come from sickle trait paired with a different hemoglobin trait, like hemoglobin C or beta thalassemia trait. That's why testing both partners for hemoglobin traits together matters.
Sickle cell disease affects about 1 in 365 Black American births.
"But I was tested as a baby"
Every US state screens newborns for sickle cell disease, and that test also shows sickle cell trait. But many adults never got their result, or don't remember it. If you don't know, a simple blood test as an adult will tell you.
How to get tested
- Hemoglobin electrophoresis or HPLC: the standard test. It shows sickle trait and other hemoglobin traits like HbC and beta thalassemia.
- A "sickle solubility" test is a quick screen, but it can't tell trait from disease or find other hemoglobin traits, so it isn't enough for family planning.
- A carrier screen covers sickle cell alongside hundreds of other conditions.
See the common conditions for your couple in the carrier odds calculator.
If you both have it
A genetic counselor can walk you through options: testing during pregnancy, IVF with embryo testing, or going ahead fully informed. Sickle cell disease care has improved a lot, including newer treatments, but knowing early gives you every choice.
General information, not medical advice.