Bonnevie-Ullrich syndrome - Diagnosing Turner syndrome

Turner syndrome is usually identified during childhood or at puberty. However, it can sometimes be diagnosed before a baby is born.

Pregnancy and birth

Turner syndrome may be suspected in pregnancy during a routine ultrasound scan (where high frequency sound waves are used to create an image of the developing baby).

Lymphoedema, a condition that causes swelling in the body’s tissues, can affect unborn babies with Turner syndrome, and may be visible on an ultrasound scan.

If Turner syndrome is suspected, further prenatal tests can confirm it, such as:

• chorionic villus sampling – a sample of cells is taken from the placenta and tested for genetic conditions; the placenta is the organ that links the mother’s blood supply to her unborn baby’s
• amniocentesis – a sample of amniotic fluid is tested for genetic conditions; amniotic fluid is the fluid that surrounds the developing baby in the womb

Sometimes Turner syndrome is diagnosed at birth as a result of heart or kidney problems, or swelling of the hands and feet (lymphoedema).

Childhood

If a girl has the typical characteristics and symptoms of Turner syndrome, such as a webbed neck, broad chest and widely spaced nipples, the syndrome may be suspected.

Short height and undeveloped ovaries are the two main features of Turner syndrome, so it's often identified during early childhood when these features become noticeable.

In some cases, Turner syndrome is not diagnosed until puberty (sexual maturity) when breasts don't develop and monthly periods do not start.

A child’s height is usually closely related to the height of their parents. Girls with Turner syndrome are typically short in relation to the height of their parents. So, an affected girl who has two tall parents may be taller than some of her peers, and is less likely to be identified based on her poor growth. 

Karyotypying

Karyotyping is a test that involves analysing chromosomes (the thread-like structures inside all human cells).

Karyotyping is often used where Turner syndrome is suspected. The test can either be carried out while the baby is inside the womb by taking a sample of amniotic fluid, or it can be carried following birth by taking a blood sample.