Most people receive one sex chromosome, an X or Y, from each parent. Two X chromosomes signifies a female. But in about 1 in 2,000 to 2,500 births, a baby girl has a missing or partially missing X chromosome. This condition is known as Turner syndrome.

Turner syndrome is typically diagnosed at an early age. Because of the missing genes, many girls affected by the disorder have physical abnormalities. They are usually short in stature (on average, their height doesn’t exceed 4 feet 8 inches) and may also have drooping or lazy eyes, low-set ears, a receding lower jaw, a webbed neck, a broad chest, and flat feet. At birth, a girl with Turner syndrome also tends to have swollen hands and feet. If a physician suspects the disorder, he or she will conduct a karyotype—a snapshot of a person’s complete chromosomal lineup—to screen for the condition.

Besides the visible symptoms, females with Turner syndrome are affected in other ways, as well. Many are born without fully functioning ovaries. Without these female reproductive organs, their bodies produce insufficient amounts of estrogen. As a result, most girls with Turner syndrome fail to undergo many of the changes associated with puberty, such as developing breasts or menstruating. What’s more, they’re also at greater risk for heart defects, kidney problems, hypothyroidism, and scoliosis.

Once a girl is diagnosed with Turner syndrome, she typically requires frequent monitoring by a physician. Growth hormones and estrogen therapy can help her develop properly. Because hearing loss is common among these children, a hearing aid may also be necessary.

ADDITIONAL FACTS

  1. Turner syndrome is named after the American endocrinologist Henry Turner (1892–1970). He first noted the symptoms of the condition in 1938.
  2. Only girls can have Turner syndrome.