Supposing someone's mother is greek/macedonian and their father is african-american/dominican, what's the chance of the child getting the sickle cell trait?

Testing for parents: Only way to know is for parents to be tested first. Any ethnicity can carry the gene for sickle cell. To get sickle cell trait, just one of the parents needs to also have it. In this case, the child has 50% chance of inheriting it. If one of the parents has sickle cell disease, 100% chance that child will get trait. If both parents trait, then 25% no trait, 25% sickle cell disease, 50% trait.