Turner Syndrome (TS) is a condition in which a woman is born without a second X chromosome. It currently affects 60,000 women in the United States.
This genetic disorder occurs in about 1 of 2,500 live births worldwide. Each year 800 new cases are diagnosed in the United States.
Variations occur in which the afflicted woman has a partial second X chromosome. Normally, an X and Y chromosome result in a male offspring while two X chromosomes create a female. Women with Turner Syndrome appear female despite the fact that they have only one sex chromosome. With only one X chromosome, the body "defaults" to female development.
Turner Syndrome Diagnosis
Turner Syndrome can be diagnosed during pregnancy with amniocentesis. For unknown reasons 98% of Turner Syndrome-afflicted fetuses spontaneously abort, making up 10% of all miscarriages. Later in life the disorder can be diagnosed by karyotyping. This chromosome test shows whether or not the second X is missing or damaged.
Symptoms of Turner Syndrome
Universal symptoms include a short stature and failure of the ovaries to develop properly. Other symptoms that may be present include a broad chest with widely spaced nipples, low hairline, low-set ears, swelling of the hands and feet, a webbed neck, small lower jaw, in-turned elbows, Simian crease, drooping eyelids and increased risk of developing heart, kidney, and thyroid problems.
Many women with TS have skeletal deformities, due in large part to hormonal problems. Generally the woman's head, neck, and chest are of normal size, but her arms and legs are proportionately short. The average height she will grow to is 4 feet 7 inches. A poor circulation of estrogen may also lead to osteoporosis.
Nearly all women with Turner Syndrome are infertile. Pregnancies are very rare and limited to those with at least a partial second X chromosome. The women who are able to get pregnant have a higher risk for miscarriages and birth defects.
Turner Syndrome Treatments
Since Turner Syndrome is a chromosomal disorder, no cure exists. Currently there are several ways of treating its symptoms. Growth hormones are approved to help girls reach a greater height. Treatment can begin as early as 2 to 3 years of age and can add 3 to 5 inches to the girl’s height.
Once growth hormone treatment is stopped, around 12 years of age, it is common to begin estrogen replacement therapy. The estrogen therapy helps the girl develop breasts and start a monthly period, but due to a lack of ovarian development that cannot be corrected she will still remain infertile. Some TS women have found success with in vitro fertizilation, however the procedure is highly risky and not typically recommended.
Cognitive Problems and Turner Syndrome
Unlike many chromosomal disorders, Turner Syndrome is not associated with mental retardation. However, some women do report learning difficulties, especially with spatial concepts such as mathematics. Researchers believe studying the effects of Turner Syndrome may hold clues to gender’s role in brain development.
Living with Turner Syndrome
Clearly these young women face many challenges in living with such a disorder. Though they may have increased health risks and face some learning difficulties, with proper treatments and counseling, all evidence suggests these girls can live full, healthy lives. Early diagnosis is critical for these girls to develop into their full potential.
References
- Ranke, M.B. "Turner Syndrome." European Journal of Endrocrinology 141 (1999): 216-217
- Stenberg, Annika, Olle Nylen, Marriane Windh, Malou Hultcrantz. "Otological Problems in Children with Turner’s Syndrome." Hearing Research. 124 (1998) 85-90
- Lawrence, Kate, Lonna Kuntsi, Michael Coleman, Ruth Campbell, David Skuse. "Face and Emotion Recognition Deficits in Turner Snydrome: A Possible Role for X-Linked Genes in Amygdala Development." American Psychological Association 17 (2003) 39-49
- Gravholt, Claus, Birgit Svenstrupt, Paul Bennett, and Jens Christiansen. "Reduced Androgen Levels in Adult Turner Syndrome: Influence of Female Sex Steroids and Growth Hormone Status." Clinical Endocrinology 50 (1999): 791-800
- National Human Genome Research Institute https://www.genome.gov/19519119/