Turner syndrome is a genetic condition that occurs only in females. Female cells normally have two X chromosomes. In Turner syndrome, cells are missing all or part of an X chromosome.

Humans have 46 chromosomes. Chromosomes contain all of your genes and DNA, the building blocks of the body. Two of these chromosomes, the sex chromosomes, determine if you become a boy or a girl. Females have two of the same sex chromosomes, written as XX. Males have an X and a Y chromosome (written as XY).

In Turner syndrome, a female does not have the usual pair of two complete X chromosomes. Most commonly, the female patient has only one X chromosome. Others may have two X chromosomes, but one of them is incomplete. Sometimes, a female has some cells with two X chromosomes, but other cells have only one.

Turner syndrome occurs in about 1 out of 2,000 live births.

Possible symptoms include a combination of:

• Short height
• Webbed neck
• Drooping eyelids
• Broad, flat chest shaped like a shield
• Absent or incomplete development at puberty, including sparse pubic hair and small breasts
• Infertility
• Dry eyes
• Absent menstruation
• Vaginal dryness, can lead to painful intercourse

Turner syndrome can be diagnosed at any stage of life. It may be diagnosed before birth if karyotyping is done during prenatal testing.

The doctor will perform a physical exam and look for signs of underdevelopment. Infants with Turner syndrome often have swollen hands and feet.

The following tests may be performed:

• Karyotyping
• Ultrasound of reproductive organs and kidneys
• Pelvic exam
• Serum luteinizing hormone levels (may be high)
• Serum follicle stimulating hormone levels (may be high)
• Echocardiogram (heart ultrasound)
• MRI of the chest

Turner syndrome may also alter the results of the following tests:

• Estriol - urine
• Estriol - serum
• Estradiol