How do people get Turner syndrome?
Normally, females inherit one X chromosome from their mother and one X chromosome from their father. But females who have Turner syndrome are missing one of their X chromosomes. Turner syndrome is typically caused by what is called nondisjunction. If a pair of sex chromosomes fails to separate during the formation of an egg (or sperm), this is referred to as nondisjunction. When an abnormal egg unites with a normal sperm to form an embryo, that embryo may end up missing one of the sex chromosomes (X rather than XX). As the embryo grows and the cells divide, every cell of the baby’s body will be missing one of the X chromosomes. The abnormality is not inherited from an affected parent (not passed down from parent to child) because women with Turner syndrome are usually sterile and cannot have children. In about 20 percent of Turner syndrome cases, one X chromosome is abnormal. It may be shaped like a ring, or missing some genetic material. About 30 percent of girls with the disorder are
