Hemoglobin Traits

People who inherit one sickle cell gene and one normal gene have sickle cell trait (SCT). People with SCT usually do not have any of the symptoms of sickle cell disease (SCD), but they can pass the trait on to their children.

If both parents have sickle cell trait (SCT), there is a 50% (or 1 in 2) chance, with each pregnancy, that any child of theirs also will have SCT, if the child inherits the sickle cell gene from one of the parents. Such children will not have symptoms of SCD, but they can pass SCT on to their children.
If both parents have SCT, there is a 25% (or 1 in 4) chance that any child of t heirs will have SCD. There is the same 25% (or 1 in 4) chance that the child will not have SCD or SCT.
If one parent has SCT, there is a 50% (or 1 in 2) chance that any child of this parent will have SCT and an equal 50% chance that the child will not have SCT.