Turner's Syndrome (gonadal dysgenesis) is usually caused by a missing X chromosome - a 45 XO karyotype. However other chromosomal abnormalities may cause the same syndrome, such as having and X chromosome located abnormally in a psudoaotosomal area shox gene. Girls with Turner's syndrome are at an increased risk for aortic dissection, and should have an evaluation of their aorta for any anuerysm or other abnormalities. Kidney abnormalities are also common and an evaluation of the kidneys is a good idea.

Most girls with Turner's syndrome are of short stature and never enter puberty; however, about 20% of girls will have some menstrual periods which then stop after a few months or years. Girls with Turner's syndrome are short, but height can be improved with administration of growth hormone and oxandrolone. Keloiding (large scars occurring in areas of skin piercing) is very common; don't pierce the ears, since unsightly keloid scarrs may result.