What Student Need to Know about Autosomal Recessive Inheritance.

Autosomal recessive inheritance means that the gene is located on one of the autosomes (chromosome pairs 1 through 22). This means that males and females are equally affected. “Recessive“ means that two copies of the gene are necessary to have the trait, one inherited from the mother, and one from the father. A person who has only one recessive gene is said to be a “carrier“ for the trait or disease, but they do not have any health problems from “carrying“ one copy of the gene. Most people do not know they carry a recessive gene for a disease until they have a child with the disease. Once parents have had a child with a recessive trait or disease, there is a one out of four, or 25 percent chance, with each subsequent pregnancy, for another child to be born with the same trait or disorder. In an autosomal recessive disorder, two changed copies of a gene are inherited—one from each of the parents—which causes the child to have the disorder. The child is called “affected” because