Turner mosaic syntrome 45xo(11%)/46xx(89%)

[Alexts]

Hello,
My wife is 23 wks pregnant with a girl. A number of days ago we got the results of the amnio fluid test which have shown that the fetus has turner mosaic 45x0/46xx with 30% of abnormal cells. We insisted on doing the FISH test to confirm the result. In the FISH test only 11% of cells (172 cells were tested) were found with turner 45xo, others were normal. Since the FISH test is performed directly on the cells taken from the amnio fluid we may assume that this result is more precise than the first test that had been performed on cultured cells. It should also be noted that so far the fetus develops absolutely fine and all ultrasound tests done so far were absolutely normal with no signs of any kind of patology.
We went to genetic counseling and they explained us the symptoms of Turner syndrom (syndrome) and told that with the mosaic of 11% the symptoms are expected to  be milder (taking into cosideration also that there is nothing abnormal seen on US). Nevertheless, some doctors told us not to take chances and recommeded to stop the pregnancy.
It is a very hard decision to make. My question is: Can anyone tell us what is the probability that our girl will have the symptoms of turner, such as short height, infertility and other problems based on what we know so far - 11% of 45xo and absolutely normal US at 23 weeks. Are there any additional tests that can be done?    

Unfortunately we don't have much time, since if we decide to stop the pregnancy it must be done next week.
Thank you in advance,
Alex

[Jordanna Joaquina, MS, CGC]

In general, females with mosaic Turner syndrome have milder symptoms than females with Turner syndrome in which we cannot identify mosaicism.

According to information from the Turner Syndrome Society of the United States (Guide for Families), "Girls with mosaicism vary more in their growth, but 50% still fall to
below the 5th percentile by about 2 years of age. Growth continues to
be slower than normal throughout childhood..." and "Ten to 15 percent of girls who have a 45X karyotype and about one-third of girls with mosaicism have some signs of breast
development in their early teens, and some will menstruate. In these girls, sexual development and menstruation usually stop sooner than usual."

Regarding prenatal test results, the percentage of mosaic cells on any one test cannot predict clinical severity as it does represent the percentage of affected cells in every tissue of the body.

We recommend that you meet with a medical geneticist, who can discuss with you and your wife the clinical symptoms of Turner syndrome and what to expect based on your test results. A medical geneticist can be found at the American College of Medical Genetics website. We wish you the best!