Turner syndrome

Only your daughter’s healthcare provider can determine what might be affecting the way she walks. We can provide you with general information on hip dysplasia and Turner syndrome, which we hope you find helpful.

Turner syndrome is caused by a female having one normal X chromosome in each of her cells, while the other sex chromosome is either missing or structurally abnormal. Females without Turner syndrome have 2 full X chromosome in all of their cells, and males have one X chromosome and one Y chromosome. The missing genetic material affects development before and after birth.

Most females with Turner syndrome are missing the second sex chromosome in all of their cells. This is also referred to as having monosomy X. This form results from a random error in an egg or sperm cell prior to conception.

Some females with Turner syndrome have two X chromosomes, but one of them is missing a piece (has a deletion). Depending on the specific gene(s) that are missing, features of Turner syndrome may or may not be present. A deletion may occur sporadically (not inherited) or it may be inherited from a parent.

Mosaic Turner syndrome (when some cells have one X chromosome and some have two sex chromosomes) is caused by a random error in early fetal development (shortly after conception).

It is still unclear exactly which genes on the X chromosome are associated with each feature of Turner syndrome. It is known that the SHOX gene on the X chromosome is important for growth and bone development. A missing copy of this gene is thought to result in the short stature and skeletal abnormalities in many affected women.

Most cases of Turner syndrome are not inherited. Most commonly, Turner syndrome occurs due to a random event during the formation of an egg or sperm cell in a parent (prior to conception). For example, if an egg or sperm cell mistakenly loses a sex chromosome, and joins at conception with an egg or sperm containing an X chromosome, the resulting child will have a single X chromosome in each cell.

Mosaic Turner syndrome, occurring when a person has some cells with one X chromosome and some cells with two X chromosomes, is also not inherited. This also occurs due to a random event, during early fetal development rather than before conception.

In rare cases, Turner syndrome may be caused by a missing piece (partial deletion) of the X chromosome. A deletion can be inherited from a parent.

Genetic testing of an affected fetus or child can identify the type of Turner syndrome present and may help to estimate the risk of recurrence. People with questions about genetic testing or recurrence risks for Turner syndrome are encouraged to speak with a genetics professional. Please visit our page on how to find a genetic clinic.

There is wide variation in features that have been reported in individuals with a 45,X/46,XY karyotype (a form of Turner syndrome mosaicism). Studies have reported that 90 percent of individuals diagnosed before birth (prenatally) have normal male appearance at birth, while those diagnosed after birth (postnatally) show a wide spectrum of features, ranging from "classic" Turner syndrome, mixed gonadal dysgenesis (the presence of some male structures as well as a uterus, vagina, and fallopian tubes), and male pseudohermaphroditism (genitalia are of one sex, but some physical characteristics of the other sex are present) to apparently normal male. There may be a risk for late-onset abnormalities, such as testicular problems leading to infertility or cancer, and short stature, which could be improved with growth hormone therapy. Classic Turner syndrome features seem to be the most common features. Mild intellectual disabilities and signs of autism have also been reported.

People with Turner syndrome may have developmental delays and/or a learning disability. It has been estimated that around 10% of children with Turner syndrome have developmental delays, and up to 70% of girls and women with Turner syndrome have disabilities affecting their nonverbal perceptual motor and visuospatial skills.

You can find further details regarding nonverbal learning disability at the following link to the University of Michigan Web site:
http://www.med.umich.edu/yourchild/topics/nld.htm

The University of Wisconsin’s Family Village Web site lists additional resources on nonverbal learning disability at the following link:
http://www.familyvillage.wisc.edu/lib_nvld.html

The Turner Syndrome Society provides further information and supportive resources for individuals and families regarding learning in girls and women with Turner syndrome at the following links:
http://www.turnersyndrome.org/intelligence.htm
http://www.turnersyndrome.org/nld.htm
http://www.turnersyndrome.org/iep.htm

You can also contact the Turner Syndrome Society directly for further information on this topic.

Turner Syndrome Society of the United States
10960 Millridge North Drive, Suite 214A
Houston, TX 77070
Toll-Free: 800-365-9944
Phone: 832-912-6006
Fax: 832-912-6446
E-mail: tssus@turnersyndrome.org
Web site: http://www.turnersyndrome.org

In addition, you can find comprehensive information on learning in girls and women with Turner syndrome through http://PubMed.gov/, a searchable database of biomedical journal articles. Click here to view a sample search.

Below are a number of references on this topic which may be of interest to you.

Hong D, Scaletta Kent J, Kesler S. Cognitive profile of Turner syndrome. Dev Disabil Res Rev. 2009;15(4):270-8.

Ross J, Roeltgen D, Zinn A. Cognition and the sex chromosomes: studies in Turner syndrome. Horm Res. 2006;65(1):47-56. Epub 2006 Jan 4.

Kesler SR. Turner syndrome. Child Adolesc Psychiatr Clin N Am. 2007. Jul;16(3):709-22.

Ross JL, Stefanatos GA, Kushner H, Zinn A, Bondy C, Roeltgen D. Persistent cognitive deficits in adult women with Turner syndrome. Neurology. 2002 Jan 22;58(2):218-25.

Mazzocco MM, Singh Bhatia N, Lesniak-Karpiak K. Visuospatial skills and their association with math performance in girls with fragile X or Turner syndrome. Child Neuropsychol. 2006 Apr;12(2):87-110.

Ross J, Zinn A, McCauley E. Neurodevelopmental and psychosocial aspects of Turner syndrome. Ment Retard Dev Disabil Res Rev. 2000;6(2):135-41.

Temple CM, Carney RA. Intellectual functioning of children with Turner syndrome: a comparison of behavioural phenotypes. Dev Med Child Neurol. 1993 Aug;35(8):691-8.

Although not all of the articles are available for free online, most articles listed in PubMed have a summary available. To obtain the full article, contact a medical/university library or your local library for interlibrary loan. You can also order articles online through the publisher’s Web site. The National Library of Medicine (NLM) Web site has a page for locating libraries in your area that can provide direct access to these journals (print or online). The Web page also describes how you can get these articles through interlibrary loan and Loansome Doc (an NLM document-ordering service). You can access this page at the following link http://nnlm.gov/members/. You can also contact the NLM toll-free at 888-346-3656 to locate libraries in your area.

The following organization provides information and resources to parents of children with a variety of disabilities. They may be able to direct you to appropriate resources, organizations, and services in your state.

National Dissemination Center for Children with Disabilities
P.O. Box 1492
Washington, DC 20013
Toll free/TTY: (800) 695-0285
Fax: (202) 884-8441
E-mail: nichcy@aed.org
Web site: http://www.nichcy.org

Approximately 2 to 5 percent of all individuals with Turner syndrome experience menstruation without medical intervention. Some teenagers with this condition begin menstruating, but cease further menses during the later teen years. A few women with Turner syndrome have apparently normal ovarian function with regular menses until the mid-20s before ovarian failure occurs.

Hip dysplasia, also known as developmental dysplasia of the hip, is a dislocation or instability of the hip joint that is present at birth. Hip dysplasia occurs more frequently in girls with Turner syndrome than in the general population. The affect of hip dysplasia depends, in part, on its severity. Dislocations in only one hip can cause one leg to be longer than the other, which can lead to walking (gait) problems and pain in the hips and knees. As individuals with Turner syndrome get older, hip dysplasia can contribute to the development of arthritis in the hips.

Treatment options for hip dysplasia are tailored for each individual and should be discussed with an orthopedist on a case by case basis. Treatment depends, in part, on the patient's age and the severity of hip dysplasia.

Typically, infants are placed in a non-surgical harness to keep the legs apart and turned outward (frog-leg position) in order to hold the hip joint in place while the child grows. Alternatively, a cast may be placed on the child's leg and changed as the child grows.

Hip dysplasia detected in an older child or young adult may be associated with worse outcomes and usually requires complex surgery to correct the problem. If left untreated, hip dysplasia will lead to arthritis and deterioration of the hip.

Your health care provider can help you determine whether your hormone levels are within the normal range. About 2-5% of individuals with Turner syndrome have spontaneous periods and have the potential to achieve pregnancy without medical intervention. However, many affected women have absent or decreased ovarian function and need hormone therapy to achieve their period.

Studies suggest that dating and initiation of sexual activities may be somewhat delayed or infrequent for some women with Turner syndrome. This may be due to a genetic or hormonal influence, or may be a result of self-esteem issues experienced by many affected women.

A 2008 study by Sheaffer AT et al examined factors that might influence sexual function in women with Turner syndrome. They reported that women with Turner syndrome who were in a partner relationship (30% of those surveyed) reported relatively normal overall sexual function, but the majority of unpartnered women reported very low level sexual functioning. Estrogen use, testosterone levels, and age of puberty did not appear to influence sexual function.

To view selected full-text journal articles on this topic, click here.

In Turner syndrome, an individual does not have the usual pair of two complete X chromosomes. The most common scenario is that a girl has only one X chromosome in all of her cells. However, some girls with Turner syndrome have a full or partial absence of the X chromosome in only some of their cells. When an individual has a different chromosomal content in his/her cells, it is called mosaicism. When some of the cells have one X chromosome and no other X or Y chromosome, and other cells have either the usual two sex chromosomes (two X's or one X and one Y) or other chromosomal differences, it is called mosaic Turner syndrome. Mosaic Turner syndrome, like Turner syndrome, is not typically inherited. It occurs as a random event during cell division in early fetal development. Other sex chromosome abnormalities are also possible in individuals with X chromosome mosaicism. Mosaicism of both the X and the Y chromosome is a common finding in Turner syndrome.

The features of mosaic Turner syndrome can vary considerably from individual to individual. In females, they can range from mild to severe signs and symptoms of Turner syndrome. In males, they can range from a seemingly normal male to the presence of a variety of features which can include dysmorphic (abnormally formed) features, mild intellectual disabilities, infertility, Ulrich-Turner stigmata (drooping of upper eyelid, extra “webbing” on the neck), gonadal dysgenesis, infertility, low testosterone levels, and azoospermia (having no sperm).

In general, Turner syndrome is considered to be a sporadic condition. Recurrence in subsequent pregnancies is rare, but has occurred. It is assumed that the likelihood of recurrence is similar to that in the general population (in other words, no increased risk for couples who have had a previous affected pregnancy). To our knowledge, there also is no increased risk for other types of genetic abnormalities.

People who have had a previous fetus or infant with Turner syndrome may consider chromosome analysis in a subsequent pregnancy, for reassurance. The optimal time to determine risks and discuss prenatal testing is prior to pregnancy. People with questions about genetic testing and recurrence risks are strongly encouraged to speak with a genetic counselor or other genetics professional.

While Turner syndrome is not common (about 1 in 2500 live female births), approximately 1 to 2% of all embryos have Turner syndrome - but 99% of these miscarry, usually during the first trimester. Turner syndrome may cause up to 10% of all first trimester miscarriages.

Women with Turner syndrome who conceive naturally have a 30% chance of having a fetus with chromosome abnormalities or congenital anomalies (birth defects) and should be offered prenatal testing. For affected women who conceive using egg donation, whether prenatal testing is recommended depends on the age of the egg donor.

The Turner Syndrome Society of the United States has a “Professional Directory” on their Web site which lists the names and contact information for professionals familiar with Turner syndrome. Click on the link above to view this directory.

The long-term outlook (prognosis) for people with Turner syndrome is typically good. Life expectancy is slightly shorter than average but may be improved by addressing and treating associated chronic illnesses, such as obesity and hypertension. Regular checkups have shown substantial improvements in the quality and length of life for women with Turner syndrome. While almost all women are infertile, pregnancy with donor eggs and assisted reproductive technology is possible. Even with growth hormone therapy, most affected people are shorter than average.

Sutton EJ, McInerney-Leo A, Bondy CA, Gollust SE, King D, Biesecker B. Turner syndrome: four challenges across the lifespan. Am J Med Genet A. 2005;139(2):57-66.

Carel JC, Elie C, Ecosse E, Tauber M, Leger J, Cabrol S, Nicolino M, Brauner R, Chaussain JL, Coste J. Self-esteem and social adjustment in young women with Turner syndrome--Influence of pubertal management and sexuality: population-based cohort study. J Clin Endocrinol Metab. 2006;91(8):2972-2979.

Frías JL, Davenport ML. Health Supervision for Children With Turner Syndrome. Pediatrics. 2003;111(3):692-702.