(Also may be referred to as: 45,X, Monosomy X, Mosaic Turner syndrome, Turner’s syndrome, Ullrich-Turner syndrome)
If you have just found out through prenatal testing that your baby has or may have Turner syndrome and are looking for more information, the Genetic Support Foundation is a good starting point.
There are many other important resources out there, including your doctor and genetic counselor. We have also compiled a list of resources that can provide you with additional information and support. After reviewing the information below, if you have a question that you are having difficulty finding an answer for, please feel free to contact us.
Turner Syndrome is a condition that occurs in girls and results when a baby has only one full copy of the X chromosome in some or all of her cells, instead of the typical two X chromosomes. This condition causes a variety of physical and health conditions including shorter than average height, infertility and a higher chance of heart defects. Individuals with Turner syndrome typically have intelligence in the normal range, although some specific learning disabilities are common that can be supported. Some individuals with Turner syndrome have more significant health and developmental concerns, while other women may have few if any notable features and not even know that they have Turner syndrome.
Turner syndrome occurs when one complete X chromosome is present in a female’s cells and the other sex chromosome is missing or structurally altered.
Some individuals with Turner syndrome have monosomy X, which means every cell in the individual’s body has only one copy of the X chromosome instead of the usual two sex chromosomes. Some individuals are said to have mosaic Turner syndrome, meaning that some cells have one X chromosome and other cells have two X chromosomes. Some individuals have one complete X chromosome and one X chromosome which has been altered in some way.
It is important to remember that the signs and symptoms of Turner syndrome can vary quite a bit from person to person. During pregnancy, Turner syndrome may be diagnosed through genetic testing such as a chorionic villus sampling (CVS) or amniocentesis. Turner syndrome may be suspected through a blood test such as cfDNA or due to findings on ultrasound such as increased fluid collection at the back of the baby’s neck (cystic hygroma), or through findings that suggest kidney or heart defects. Keep in mind that cfDNA and ultrasound cannot tell for certain if a baby has Turner syndrome.
During the newborn period, a diagnosis of Turner syndrome may be suspected based on increased swelling of the hands or feet (due to lymphedema). Some babies and girls with Turner syndrome have the appearance of a “webbed neck” which means there can appear to be extra skin at the sides of the neck. There is a higher chance for a cleft palate as well as hearing and vision problems.
In girls and women with Turner syndrome, short stature is the most common finding. Individuals with Turner syndrome often do have some subtle facial similarities to other people with Turner syndrome. There is also a higher chance for heart and kidney conditions and scoliosis associated with Turner syndrome. Most individuals with Turner syndrome are infertile and most girls due need hormone therapy to cause the growth and development associated with puberty.
As women with Turner syndrome grow older, there is some higher risk for a range of conditions including osteoporosis, thyroid disorders, kidney and digestive issues.
In most cases, the chance that a women will have another baby with Turner syndrome is thought to be less that 1% and the majority of cases of Turner syndrome are not inherited. With monosomy X, when every cell in the individual has only one X chromosome, the chromosomal abnormality happens as a random event during the formation of the egg or sperm cell. Mosaic Turner syndrome is also not inherited, but occurs after conception, usually early in the development of the growing baby. In this case, some of the individual’s cells would have one X chromosome and other cells would have two sex chromosomes. In rare cases, Turner syndrome is caused by a structural change on one X chromosome that can be passed from one generation to the next.
There is no “cure” for Turner syndrome as the genetic change that causes this condition is typically present in some or all of the cells in the person’s body.
Individuals who have Turner syndrome will need to undergo regular checks of their heart to monitor for new concerns or changes. Regular check-ups of the eyes, kidneys and thyroid are also important.
Early intervention and support in school can help with learning disabilities. Many girls with Turner syndrome are given growth hormone to support them growing to a taller height and many will also need hormone support to go through normal pubertal development..
Turner syndrome occurs in about 1 in 2,500 newborn girls. Pregnancies with Turner syndrome are often lost as miscarriages and stillbirths.
Most women with Turner syndrome will be shorter than average and have infertility. Some women with Turner syndrome experience difficulty in learning in some areas however, many individuals with Turner syndrome have success in school, including higher education. Women with Turner syndrome work in a variety of career settings. Some women with Turner syndrome can have children on their own or with the help of assisted reproductive technologies. Many women with Turner syndrome adopt children. Individuals with Turner syndrome will need careful monitoring of their health throughout their life.
The life expectancy with Turner syndrome may be reduced depending on health complications, however most women with Turner syndrome can expect to love full and productive lives.
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