Turner syndrome

In Turner syndrome (gonadal dysgenesis), girls are born with one of the two X chromosomes partially or completely missing.
Many newborns with Turner syndrome have swelling (lymphedema) on the backs of their hands and tops of their feet. Swelling or loose folds of skin are often evident over the back of the neck. Many other abnormalities often develop, including a webbed neck (wide skin attachment between the neck and shoulders), a low hairline at the back of the neck, a broad chest with wide-spaced nipples, and poorly developed nails.

As a girl with Turner syndrome gets older, she has no menstrual periods (amenorrhea), and the breasts, vagina, and labia remain childlike rather than undergoing the changes of puberty. The ovaries usually do not contain developing eggs. A girl or woman with Turner syndrome is virtually always short; obesity is common.

Other disorders often develop. Heart defects include narrowing of part of the aorta (coarctation of the aorta). Kidney and eye defects, diabetes mellitus, and thyroid diseases are common. Occasionally, abnormal blood vessels in the intestine cause bleeding.

Many girls with Turner syndrome have difficulty in assessing visual and spatial relationships and have problems with planning and attention. They tend to score poorly on certain performance tests and in mathematics, even if they achieve average or above-average scores on verbal intelligence tests. Mental retardation is uncommon.

A doctor may suspect the diagnosis because of the newborn's abnormal appearance. However, suspicion often does not develop until the teenage years, when the girl fails to mature sexually. Analysis of the chromosomes confirms the diagnosis.

Treatment with a hormone normally secreted from the brain (growth hormone) can stimulate growth. Treatment with the female hormone estrogen is usually not started until after satisfactory growth has been achieved. Estrogen treatment may improve planning, attention, and assessment of visual and spatial relationships as well as stimulating sexual maturation.