About sickle cell disease (SCD)

Sickle cell disease and genetics

• SCD is inherited. This inheritance means the gene mutation is passed down from parents to their children, just like traits such as eye color and hair color.
• If a person carries 1 copy of this mutated gene, they have the sickle cell (SC) trait. If they have 2 copies of the mutated gene, they will have SCD.
• The chance for disease occurs when 2 people who are carriers of the mutated gene have a child.
• When 2 individuals with the trait have a child, there is a 25% chance that the child will have the condition, a 50% chance they’ll be a carrier of the trait like their parents, and a 25% chance they will not be a carrier and will not have SCD.
• If only 1 parent is a carrier of the trait, then their child has a 25% chance of being a carrier of the trait.
• If 1 parent has SCD and the other has the trait, there is a 50% chance that the child will have SCD and a 50% chance they will be a carrier of the trait.
• When both parents have SCD, there is a 100% chance their child will also have SCD.
• If only 1 parent has SCD, then there is a 100% chance their child will be a carrier of the trait but will not have SCD.

SCD inheritance for two carriers of the trait