Turner syndrome (TS) is caused by a defect of one female sex chromosome.
Simply put, we all have a pair of sex chromosomes. Men have one X and one Y chromosome, while women have two X chromosomes. With Turner syndrome, one female X chromosome is normal, while the other only partially exists—or it may be completely missing.
Your sex chromosomes determine your biological sex. Each sex chromosome contains genes that control your physical and hormonal features. If you have Turner syndrome, certain features will not develop or function as they should because you're missing all or part of a chromosome.
Researchers have spent years trying to determine which genes on the X chromosome cause the abnormalities of Turner syndrome. In 1997, scientists made a significant discovery—the short stature homeobox (SHOX) gene.
The SHOX gene plays a large role in determining height and bone growth. It is located on the X chromosome in both men and women. When all or part of an X chromosome is missing, so is the SHOX gene. This accounts for the short stature commonly associated with Turner syndrome.
The medical community does not fully understand why these chromosomal abnormalities occur. However, they believe it is not an inherited condition. Also, they know that parents do not cause—and cannot prevent-Turner syndrome in —their daughters.