Turner Syndrome

What is Turner syndrome?

Turner syndrome is a chromosomal abnormality that only occurs in females. It can be diagnosed at any point in life, even before birth.

Girls with Turner syndrome at full growth are shorter than average, have a high palate, and are not able to reproduce because their ovaries do not develop as expected. Common physical characteristics may also include webbing on the neck, low-set ears, very angled elbows, a low hairline, and a small jaw. These girls may also experience kidney and thyroid problems, as well as diabetes and osteoporosis.

Some girls with this syndrome do not show any symptoms or clinical features. Others show just one or two, or a combination.

Turner syndrome occurs in 1 out of every 1,500 to 2,500 female births.

Turner Syndrome Karyotype
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Normally there are two copies of the X chromosome in girls. Turner syndrome occurs when there is only one X chromosome.

What causes Turner syndrome?

Turner syndrome is caused when one of the two X chromosomes normally found in females is missing or damaged. This happens randomly.

Turner syndrome is diagnosed through a blood test designed to analyze chromosomes, called a karyotype. The normal female karyotype is 46XX; the karyotype of a child with Turner syndrome is 45XO.

What heart conditions may be associated with Turner syndrome?

About 5% to 10% of girls with Turner syndrome have a heart condition, such as coarctation of the aorta. Symptoms can include heart murmur and high blood pressure, even in childhood. Bicuspid aortic valve can also be present, though this is much rarer. A heart condition, along with edema, is a key marker used to make a diagnosis shortly after birth.

What is the long-term outlook for children with Turner syndrome?

Girls with Turner syndrome have normal intelligence but they may have trouble with memory, attention, and spatial awareness. This may suggest the need for extra help during the school years. The reproductive and growth concerns are addressed by an endocrinologist, usually with growth hormones, while a cardiologist will address any heart involvement. With appropriate support, girls with Turner syndrome can lead full lives.

For more information about Turner syndrome, please ask to be referred to a genetic counsellor.

Fraser Golding, MD, FRCPC

Fraser Golding, MD, FRCPC