What is the inheritance pattern of sickle-cell anemia?

Sickle-cell anemia is inherited in an autosomal recessive manner. This means that an individual must inherit two copies of the sickle-cell gene mutation, one from each parent, to exhibit the disease. When a person has one normal gene and one sickle-cell gene, they are considered a carrier (or have sickle cell trait) but typically do not show symptoms of the disease.

In autosomal recessive conditions, both parents must be carriers of the gene for there to be a chance of passing the disorder to their children. Each child of two carrier parents has a 25% chance of being affected by the disease, a 50% chance of being a carrier, and a 25% chance of being unaffected and not a carrier. This pattern of inheritance is crucial for understanding risk factors in family planning and genetic counseling for those associated with sickle-cell anemia.