Turner syndrome is a genetic disorder that affects a girl's development. The cause is a missing or incomplete X chromosome. Girls who have it are short, and their ovaries don't work properly.
Other physical features typical of Turner syndrome are
Short, "webbed" neck with folds of skin from tops of shoulders to sides of neck
Low hairline in the back
Low-set ears
Swollen hands and feet
Most women with Turner syndrome are infertile. They are at risk for health difficulties such as high blood pressure, kidney problems, diabetes, cataracts, osteoporosis, and thyroid problems.
Doctors diagnose Turner syndrome based on symptoms and a genetic test. Sometimes it is found in prenatal testing. There is no cure for Turner syndrome, but there are some treatments for the symptoms. Growth hormone often helps girls reach heights that are close to average. Hormone replacement can help start sexual development. Assisted reproduction techniques can help some women with Turner syndrome get pregnant.
NIH: National Institute of Child Health and Human Development