Turner syndrome is a genetic disorder that occurs when a girl is born with one X chromosome (a structure of DNA that carries genes) instead of two. It can also occur when a girl is born missing part of one X chromosome. The effects of Turner syndrome vary widely from patient to patient.

Chromosomes contain the genes that determine individual characteristics such as height, blood type and eye color. At conception, each parent contributes 23 of the total 46 chromosomes. Two of these chromosomes, the sex chromosomes, determine gender. The female parent always contributes an X chromosome, and the male parent contributes either an X or Y chromosome.

When an egg is fertilized, it has either an XX chromosome and develops into a girl or an XY chromosome and develops into a boy. The loss of an X chromosome is a random occurrence during the formation of sex cells. Parents have no control over its occurrence.

Sex chromosomes play a major role in the development of reproductive tissues and organs. Therefore, the height and sexual development of females born with Turner syndrome is affected. The syndrome is a leading cause of premature ovarian failure in girls.

Turner syndrome occurs in one of every 2,000 female births worldwide, according to the National Institutes of Health (NIH). Approximately 60,000 girls and women in the United States have the condition, and 800 new cases are diagnosed each year, according to the Turner Syndrome Society.

Turner syndrome was named after Dr. Henry Turner, who first described it in 1938 when he observed short stature and incomplete sexual maturation in otherwise normal female patients. The chromosomal deficiency that causes this disorder was discovered in 1959. It is a syndrome, meaning there is a group of related characteristics but no known cause. As such, management of the condition focuses on addressing problems associated with it rather than curing the condition.

The causes or risk factors for having a daughter with Turner syndrome are not known. In addition, there is no evidence that ethnic or racial factors influence the risk of developing Turner syndrome. Advanced maternal age also does not increase a female fetus’ risk of the syndrome. Although Turner syndrome is a lifelong condition without cure, proper treatment can help patients lead normal, healthy lives.

It should be noted that Noonan syndrome, sometimes erroneously called male Turner syndrome, is a genetic disorder that can occur in both sexes. This genetic disorder is unrelated to Turner syndrome.