Because the signs of Turner syndrome (TS) are often obvious, most girls with the condition are diagnosed shortly after birth or in early childhood. But you can be diagnosed with TS at any age. In fact, there are some women who experience a normal puberty and are diagnosed with the condition later as an adult. Whatever the age, the test used to diagnose Turner syndrome is the same—and it is known as a karyotype.
A karyotype is a blood test that produces an image of your chromosomes. That way, your doctor can identify whether one of your sex chromosomes is missing or partially missing.
Prenatal and Infancy Diagnosis
Turner syndrome can be detected before the child is born. A prenatal karyotype may be ordered if an ultrasound shows that the fetus has signs of TS, such as fluid around the neck or heart problems. Karyotypes are otherwise only part of specialized testing during pregnancy, like an amniocentesis. On very rare occasions, a prenatal karyotype abnormality may be false, and the baby may have a normal karyotype at birth.
Approximately half of all girls with TS are diagnosed at birth or infancy. Certain signs, particularly swollen extremities and heart complications, warrant a karyotype test—even if prenatal karyotypes showed no problems.
Childhood and Adolescent Diagnosis
Some girls aren't diagnosed with Turner syndrome until later in childhood or adolescence. The signs of the disorder may have been subtle for a few years, but they can become more apparent as girls reach their teen years. At this point, girls with Turner syndrome may be noticeably shorter than other girls their age or may not have reached puberty. These are signs that a karyotype may then be necessary.
Being diagnosed with TS as an adult is fairly uncommon. A small amount of women may have Turner syndrome but have a normal puberty. At some point, however, their ovaries stop working, estrogen production ceases, and they experience premature menopause. Some women with Turner syndrome first suspect that something is wrong when they can't get pregnant, so they consult their gynecologist to determine what's wrong. While hormone testing may show a low estrogen level, a karyotype test is necessary for a definite TS diagnosis.
Understanding the signs of TS is essential in knowing when to talk to your doctor about karyotype testing. Getting an early diagnosis for Turner syndrome is important so that you can explore options for timely growth hormone treatment and estrogen replacement therapy.